scsi: lpfc: Check queue pointer before use

The queue pointer might not be valid. The rest of the code checks the
pointer before accessing it. lpfc_sli4_process_missed_mbox_completions is
the only place where the check is missing.

Fixes: 657add4 ("scsi: lpfc: Fix poor use of hardware queues if fewer irq vectors")
Cc: James Smart <jsmart2021@gmail.com>
Link: https://lore.kernel.org/r/20191018162111.8798-1-dwagner@suse.de
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_sli.c

@@ -7866,7 +7866,7 @@ lpfc_sli4_process_missed_mbox_completions(struct lpfc_hba *phba)
 	if (sli4_hba->hdwq) {
 		for (eqidx = 0; eqidx < phba->cfg_irq_chann; eqidx++) {
 			eq = phba->sli4_hba.hba_eq_hdl[eqidx].eq;
-			if (eq->queue_id == sli4_hba->mbx_cq->assoc_qid) {
+			if (eq && eq->queue_id == sli4_hba->mbx_cq->assoc_qid) {
 				fpeq = eq;
 				break;
 			}