Fix bashism and remove useless use of cat.
--- a/tests/test-mq
+++ b/tests/test-mq
@@ -342,7 +342,7 @@ echo % create a git patch
echo a > alexander
hg add alexander
hg qnew -f --git addalexander
-cat .hg/patches/addalexander | grep diff
+grep diff .hg/patches/addalexander
echo % create a git binary patch
cat > writebin.py <<EOF
@@ -355,11 +355,11 @@ python writebin.py bucephalus
python "$TESTDIR/md5sum.py" bucephalus
hg add bucephalus
hg qnew -f --git addbucephalus
-cat .hg/patches/addbucephalus | grep diff
+grep diff .hg/patches/addbucephalus
echo % check binary patches can be popped and pushed
hg qpop
-! test -f bucephalus || echo % bucephalus should not be there
+test -f bucephalus && echo % bucephalus should not be there
hg qpush
test -f bucephalus || echo % bucephalus should be there
python "$TESTDIR/md5sum.py" bucephalus