[SCSI] lpfc: Fixes in mbox_timeout_handler

Analysis:

Timeout of READ_SPARM64 causes call to lpfc_mbox_timeout_handler which
reads psli->mbox_active to determine the timeout mbox.  Timeout
handler then NULL's psli->mbox_active and calls
lpfc_mbx_cmpl_read_sparam(), which on timeout condition, calls
link_down().  link_down() now calls disc_done() which calls
mbox_timeout_hander() again since WORKER_MBOX_TMO is still set, which
goes back to read psli->mbox_active which is already NULL'ed.

Remove redundant if statement in lpfc_mbox_timeout_handler.  pmbox is
assigned psli->mbox_active so there is no need to check if it actually
equals psli->mbox_active.
Signed-off-by: NJames Smart <James.Smart@emulex.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/lpfc/lpfc_sli.c

@@ -1724,6 +1724,8 @@ lpfc_mbox_timeout_handler(struct lpfc_hba *phba)
 		return;
 	}
 
+	phba->work_hba_events &= ~WORKER_MBOX_TMO;
+
 	pmbox = phba->sli.mbox_active;
 	mb = &pmbox->mb;
 
@@ -1738,7 +1740,6 @@ lpfc_mbox_timeout_handler(struct lpfc_hba *phba)
 		phba->sli.sli_flag,
 		phba->sli.mbox_active);
 
-	if (phba->sli.mbox_active == pmbox) {
 	phba->sli.mbox_active = NULL;
 	if (pmbox->mbox_cmpl) {
 		mb->mbxStatus = MBX_NOT_FINISHED;
@@ -1747,7 +1748,6 @@ lpfc_mbox_timeout_handler(struct lpfc_hba *phba)
 		spin_lock_irq(phba->host->host_lock);
 	}
 	phba->sli.sli_flag &= ~LPFC_SLI_MBOX_ACTIVE;
-	}
 
 	spin_unlock_irq(phba->host->host_lock);
 	lpfc_mbox_abort(phba);