t/t0600-reffiles-backend.sh: rm -v is not portable

The -v option for rm is not specified by POSIX.  The illumos
implementation of rm does not support -v.  Since we do not need the
verbose rm output we just drop -v for rm.

Signed-off-by: Marcel Telka <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: mtelka

t/t0600-reffiles-backend.sh

@@ -424,7 +424,7 @@ test_expect_success SYMLINKS 'git branch -m with symlinked .git/refs' '
 	test_when_finished "rm -rf subdir" &&
 	git init --bare subdir &&
 
-	rm -rfv subdir/refs subdir/objects subdir/packed-refs &&
+	rm -rf subdir/refs subdir/objects subdir/packed-refs &&
 	ln -s ../.git/refs subdir/refs &&
 	ln -s ../.git/objects subdir/objects &&
 	ln -s ../.git/packed-refs subdir/packed-refs &&