t1000: use "test_must_fail git frotz", not "! git frotz"

Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t1000-read-tree-m-3way.sh

@@ -214,7 +214,7 @@ test_expect_success '1 - must not have an entry not in A.' "
      rm -f .git/index XX &&
      echo XX >XX &&
      git update-index --add XX &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -254,7 +254,7 @@ test_expect_success \
      cp .orig-A/AN AN &&
      echo extra >>AN &&
      git update-index --add AN &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -271,7 +271,7 @@ test_expect_success \
      cp .orig-A/AA AA &&
      git update-index --add AA &&
      echo extra >>AA &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -280,7 +280,7 @@ test_expect_success \
      cp .orig-A/AA AA &&
      echo extra >>AA &&
      git update-index --add AA &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -306,7 +306,7 @@ test_expect_success \
      cp .orig-A/LL LL &&
      echo extra >>LL &&
      git update-index --add LL &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -314,7 +314,7 @@ test_expect_success \
      rm -f .git/index DD &&
      echo DD >DD
      git update-index --add DD &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -322,7 +322,7 @@ test_expect_success \
      rm -f .git/index DM &&
      cp .orig-B/DM DM &&
      git update-index --add DM &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -330,7 +330,7 @@ test_expect_success \
      rm -f .git/index DN &&
      cp .orig-B/DN DN &&
      git update-index --add DN &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -347,7 +347,7 @@ test_expect_success \
      cp .orig-A/MD MD &&
      git update-index --add MD &&
      echo extra >>MD &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -356,7 +356,7 @@ test_expect_success \
      cp .orig-A/MD MD &&
      echo extra >>MD &&
      git update-index --add MD &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -373,7 +373,7 @@ test_expect_success \
      cp .orig-A/ND ND &&
      git update-index --add ND &&
      echo extra >>ND &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -382,7 +382,7 @@ test_expect_success \
      cp .orig-A/ND ND &&
      echo extra >>ND &&
      git update-index --add ND &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -399,7 +399,7 @@ test_expect_success \
      cp .orig-A/MM MM &&
      git update-index --add MM &&
      echo extra >>MM &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -408,7 +408,7 @@ test_expect_success \
      cp .orig-A/MM MM &&
      echo extra >>MM &&
      git update-index --add MM &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -434,7 +434,7 @@ test_expect_success \
      cp .orig-A/SS SS &&
      echo extra >>SS &&
      git update-index --add SS &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -477,7 +477,7 @@ test_expect_success \
      cp .orig-A/NM NM &&
      git update-index --add NM &&
      echo extra >>NM &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -486,7 +486,7 @@ test_expect_success \
      cp .orig-A/NM NM &&
      echo extra >>NM &&
      git update-index --add NM &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 test_expect_success \
@@ -512,7 +512,7 @@ test_expect_success \
      cp .orig-A/NN NN &&
      echo extra >>NN &&
      git update-index --add NN &&
-     ! git read-tree -m $tree_O $tree_A $tree_B
+     test_must_fail git read-tree -m $tree_O $tree_A $tree_B
 "
 
 # #16