scsi: ufs: fix a missing check of devm_reset_control_get

devm_reset_control_get could fail, so the fix checks its return value and
passes the error code upstream in case it fails.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Acked-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>