[SCSI] qla2xxx: fix for multiqueue in MISX disabled case

 Fix to accommodate a hardware bug in multiqueue mode that does not
 work properly when acknowledgement of MSIX Interrupts is disabled.

Signed-off-by: Anirban Chakraborty <anirban.chakraborty@qlogic.com>
Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>