t7111: fix bad HEAD in tests with unmerged entries

When testing what happens on unmerged entries, the HEAD is the
commit we are starting from before the merge that fails and create
the unmerged entries. It is not the commit before.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7111-reset-table.sh

@@ -73,13 +73,13 @@ test_expect_success 'setting up branches to test with unmerged entries' '
     git checkout branch1 &&
     test_commit B1 file1 &&
     git checkout branch2 &&
-    test_commit B2 file1
+    test_commit B file1
 '
 
 while read W1 I1 H1 T opt W2 I2 H2
 do
     test_expect_success "check: $W1 $I1 $H1 $T --$opt $W2 $I2 $H2" '
-	git reset --hard B2 &&
+	git reset --hard B &&
 	test_must_fail git merge branch1 &&
 	cat file1 >X_file1 &&
 	if test "$W2" != "XXXXX"
@@ -100,14 +100,14 @@ do
 	fi
     '
 done <<\EOF
-X U C D soft   XXXXX
-X U C D mixed  X D D
-X U C D hard   D D D
-X U C D merge  D D D
-X U C C soft   XXXXX
-X U C C mixed  X C C
-X U C C hard   C C C
-X U C C merge  C C C
+X U B C soft   XXXXX
+X U B C mixed  X C C
+X U B C hard   C C C
+X U B C merge  C C C
+X U B B soft   XXXXX
+X U B B mixed  X B B
+X U B B hard   B B B
+X U B B merge  B B B
 EOF
 
 test_done