[SCSI] qla2xxx: Consolidation of SRB processing.

Rework the structures related to SRB processing to minimize the memory
allocations per I/O and manage resources associated with and completions
from common routines.

Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/qla2xxx/qla_mbx.c b/drivers/scsi/qla2xxx/qla_mbx.c
index be520a9..50ec272 100644
--- a/drivers/scsi/qla2xxx/qla_mbx.c
+++ b/drivers/scsi/qla2xxx/qla_mbx.c
@@ -874,6 +874,7 @@
 	scsi_qla_host_t *vha = fcport->vha;
 	struct qla_hw_data *ha = vha->hw;
 	struct req_que *req = vha->req;
+	struct scsi_cmnd *cmd = GET_CMD_SP(sp);
 
 	ql_dbg(ql_dbg_mbx, vha, 0x103b, "Entered %s.\n", __func__);
 
@@ -896,7 +897,7 @@
 		mcp->mb[1] = fcport->loop_id << 8;
 	mcp->mb[2] = (uint16_t)handle;
 	mcp->mb[3] = (uint16_t)(handle >> 16);
-	mcp->mb[6] = (uint16_t)sp->cmd->device->lun;
+	mcp->mb[6] = (uint16_t)cmd->device->lun;
 	mcp->out_mb = MBX_6|MBX_3|MBX_2|MBX_1|MBX_0;
 	mcp->in_mb = MBX_0;
 	mcp->tov = MBX_TOV_SECONDS;