Pull block fixes from Jens Axboe:
 "A small set of fixes that should go into this release. This contains:

   - An NVMe pull request from Christoph, with a few select fixes.

     One of them fix a polling regression in this series, in which it's
     trivial to cause the kernel to disable most of the hardware queue
     interrupts.

   - Fixup for a blk-mq queue usage imbalance on request allocation,
     from Keith.

   - A xen block pull request from Konrad, fixing two issues with
     xen/xen-blkfront"

* 'for-linus' of git://git.kernel.dk/linux-block:
  blk-mq-pci: add a fallback when pci_irq_get_affinity returns NULL
  nvme-pci: set cqe_seen on polled completions
  nvme-fabrics: fix reporting of unrecognized options
  nvmet-fc: eliminate incorrect static markers on local variables
  nvmet-fc: correct use after free on list teardown
  nvmet: don't overwrite identify sn/fr with 0-bytes
  xen-blkfront: use a right index when checking requests
  xen: fix bio vec merging
  blk-mq: Fix queue usage on failed request allocation