scsi: qla2xxx: Fix crash due to mismatch mumber of Q-pair creation for Multi queue

scsi: qla2xxx: Fix crash due to mismatch mumber of Q-pair creation for Multi queue

when driver is loaded with Multi Queue enabled, it was noticed that
there was one less queue pair created.

Following message would indicate this:

"No resources to create additional q pair."

The result of one less queue pair means that system can crash, if the
block mq layer thinks there is an extra hardware queue available, and
the driver will use a NULL ptr qpair in that instance.

Following stack trace is seen in one of the crash:

irq_create_affinity_masks+0x98/0x530
irq_create_affinity_masks+0x98/0x530
__pci_enable_msix+0x321/0x4e0
mutex_lock+0x12/0x40
pci_alloc_irq_vectors_affinity+0xb5/0x140
qla24xx_enable_msix+0x79/0x530 [qla2xxx]
qla2x00_request_irqs+0x61/0x2d0 [qla2xxx]
qla2x00_probe_one+0xc73/0x2390 [qla2xxx]
ida_simple_get+0x98/0x100
kernfs_next_descendant_post+0x40/0x50
local_pci_probe+0x45/0xa0
pci_device_probe+0xfc/0x140
driver_probe_device+0x2c5/0x470
__driver_attach+0xdd/0xe0
driver_probe_device+0x470/0x470
bus_for_each_dev+0x6c/0xc0
driver_attach+0x1e/0x20
bus_add_driver+0x45/0x270
driver_register+0x60/0xe0
__pci_register_driver+0x4c/0x50
qla2x00_module_init+0x1ce/0x21e [qla2xxx]

Cc: <stable@vger.kernel.org> # v4.10+
Signed-off-by: Sawan Chandak <sawan.chandak@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>