t8001-annotate: fix a bash-ism in this test

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>

t/t8001-annotate.sh

@@ -8,8 +8,8 @@ PROG='git annotate'
 
 test_expect_success \
     'Annotating an old revision works' \
-    '[ $(git annotate file master | awk "{print \$3}" | grep -c "^A$") == 2 ] && \
+    '[ $(git annotate file master | awk "{print \$3}" | grep -c "^A$") -eq 2 ] && \
-     [ $(git annotate file master | awk "{print \$3}" | grep -c "^B$") == 2 ]'
+     [ $(git annotate file master | awk "{print \$3}" | grep -c "^B$") -eq 2 ]'
 
 
 test_done