[SCSI] libfc: fix slowpath error from WARN_ON in fc_fcp_send_data

This is exposed by a mpio test using EMC CLARiiON targets when LUN
tresspassing happens, the burst length from the XFER_READY for the
MODE SELECT(10) is 19 bytes, much smaller than FC_MIN_MAX_PAYLOAD as
256 bytes. This patch removes the related two WARN_ON()s.
Signed-off-by: NYi Zou <yi.zou@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

drivers/scsi/libfc/fc_fcp.c

@@ -580,10 +580,8 @@ static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
 			   fsp, seq_blen, lport->lso_max, t_blen);
 	}
 
-	WARN_ON(t_blen < FC_MIN_MAX_PAYLOAD);
 	if (t_blen > 512)
 		t_blen &= ~(512 - 1);	/* round down to block size */
-	WARN_ON(t_blen < FC_MIN_MAX_PAYLOAD);	/* won't go below 256 */
 	sc = fsp->cmd;
 
 	remaining = seq_blen;