scsi: ufs: bsg: Clean up ufs_bsg_request()

Move sg_copy_from_buffer() below its associated case statement.

Signed-off-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>