common/rc: drop 'fsck -f' parameter from _repair_test_fs

common/rc: drop 'fsck -f' parameter from _repair_test_fs

The '-f' parameter is fsck.ext# specific, where it's documented to:
  Force checking even if filesystem is marked clean

_repair_test_fs() is only called on _check_test_fs() failure, so
dropping the parameter should be possible without changing ext#
behaviour.
Doing so fixes _repair_test_fs() on exfat, where fsck.exfat doesn't
support '-f'.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Zorro Lang <zlang@kernel.org>