scsi: ufs: fix wrong/ambiguous fall through comments

These aren't really falling through to anywhere meaningful.

Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>