Merge branch 'nvme-5.1' of git://git.infradead.org/nvme into for-5.1/block

Pull 5.1 NVMe material from Christoph:

"Below is our current (small) queue of NVMe patches for Linux 5.1. We
 want the re-addition of the Write Zeroes support to be in linu-next for
 a few weeks as it caused some problems last time. The only other patch
 is a cleanup from Sagi."

* 'nvme-5.1' of git://git.infradead.org/nvme:
  nvme: remove the .stop_ctrl callout
  nvme: add support for the Write Zeroes command