[SCSI] lpfc: add missed data buffer accessor

This is an addendum to:

 commit a0b4f78f9a4c869e9b29f254054ad7441cb40bbf
 Author: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
    [SCSI] lpfc: convert to use the data buffer accessors

One place was missed in the merge

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Acked-by: James Smart <James.Smart@Emulex.Com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/lpfc/lpfc_scsi.c

@@ -506,7 +506,7 @@ lpfc_handle_fcp_err(struct lpfc_vport *vport, struct lpfc_scsi_buf *lpfc_cmd,
 					"underrun converted to error "
 					"Data: x%x x%x x%x\n",
 					phba->brd_no, vpi, cmnd->cmnd[0],
-					cmnd->request_bufflen,
+					scsi_bufflen(cmnd),
 					scsi_get_resid(cmnd), cmnd->underflow);
 			host_status = DID_ERROR;
 		}