common/rc: use _try_scratch_mount for scratch_remount

When call _scratch_remount for cifs , it always requires to input
password. This will make generic/306 generic/452 failed because
cifs remount failed.

Signed-off-by: Xiaoli Feng <xifeng@redhat.com>
Reviewed-and-tested-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
2 files changed