scsi: lpfc: avoid false-positive gcc-8 warning

This is an interesting regression with gcc-8, showing a harmless warning
for correct code:

In file included from include/linux/kernel.h:13:0,
...
from drivers/scsi/lpfc/lpfc_debugfs.c:23:
include/linux/printk.h:301:2: error: 'eq' may be used uninitialized in this function [-Werror=maybe-uninitialized]
printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
^~~~~~
In file included from drivers/scsi/lpfc/lpfc_debugfs.c:58:0:
drivers/scsi/lpfc/lpfc_debugfs.h:451:31: note: 'eq' was declared here

I managed to reduce the warning into a small test case for gcc-8 that I
reported in the gcc bugzilla[1].

As a workaround, this changes the logic to move the two assignments of
'eq' out of the conditions and instead make the index conditional. This
works for all configurations I tried and avoids adding a bogus
initialization.

Acked-by: James Smart <[e-mail]>
Link: [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81958
Signed-off-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/scsi/lpfc/lpfc_debugfs.h

···
 		return;
 
 	for (eqidx = 0; eqidx < phba->io_channel_irqs; eqidx++) {
-		eq = phba->sli4_hba.hba_eq[eqidx];
-		if (cq->assoc_qid == eq->queue_id)
+		if (cq->assoc_qid == phba->sli4_hba.hba_eq[eqidx]->queue_id)
 			break;
 	}
 	if (eqidx == phba->io_channel_irqs) {
 		pr_err("Couldn't find EQ for CQ. Using EQ[0]\n");
 		eqidx = 0;
-		eq = phba->sli4_hba.hba_eq[0];
 	}
+
+	eq = phba->sli4_hba.hba_eq[eqidx];
 
 	if (qtype == DUMP_FCP || qtype == DUMP_NVME)
 		pr_err("%s CQ: WQ[Idx:%d|Qid%d]->CQ[Idx%d|Qid%d]"