scsi: qla2xxx: Changes to support kdump kernel for NVMe BFS

scsi: qla2xxx: Changes to support kdump kernel for NVMe BFS

The MSI-X and MSI calls fails in kdump kernel. Because of this
qla2xxx_create_qpair() fails leading to .create_queue callback failure.
The fix is to return existing qpair instead of allocating new one and
allocate a single hw queue.

[   19.975838] qla2xxx [0000:d8:00.1]-00c7:11: MSI-X: Failed to enable support,
giving   up -- 16/-28.
[   19.984885] qla2xxx [0000:d8:00.1]-0037:11: Falling back-to MSI mode --
ret=-28.
[   19.992278] qla2xxx [0000:d8:00.1]-0039:11: Falling back-to INTa mode --
ret=-28.
..
..
..
[   21.141518] qla2xxx [0000:d8:00.0]-2104:2: qla_nvme_alloc_queue: handle
00000000e7ee499d, idx =1, qsize 32
[   21.151166] qla2xxx [0000:d8:00.0]-0181:2: FW/Driver is not multi-queue capable.
[   21.158558] qla2xxx [0000:d8:00.0]-2122:2: Failed to allocate qpair
[   21.164824] nvme nvme0: NVME-FC{0}: reset: Reconnect attempt failed (-22)
[   21.171612] nvme nvme0: NVME-FC{0}: Reconnect attempt in 2 seconds

Link: https://lore.kernel.org/r/20210810043720.1137-13-njavali@marvell.com
Cc: stable@vger.kernel.org
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Saurav Kashyap <skashyap@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>