nvme-pci: Remove nvme_setup_prps BUG_ON

nvme-pci: Remove nvme_setup_prps BUG_ON

This patch replaces the invalid nvme SGL kernel panic with a warning,
and returns an appropriate error. The warning will occur only on the
first occurance, and sgl details will be printed to help debug how the
request was allowed to form.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit 86eea2895d11dde9bf43fa2046331e84154e00f4)

Orabug: 26871819

Conflicts:
    Added the macro BLK_STS to get status from nvme_setup_prps.

Signed-off-by: Ashok Vairavan <ashok.vairavan@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Kyle Fortin <kyle.fortin@oracle.com>
Reviewed-by: Ashish Samant <ashish.samant@oracle.com>