[PATCHv2-4.5 00/10] NVMe fixes

[Keith Busch]

Just want to point out a couple issues. Both are easy fixes and will
send in a few minutes.

First, admin queues don't have namespaces, so the new namespace state
check isn't always correct. I haven't been able to synthesize a test that
gets an admin command down this path in the disabled queue condition,
but it's clearly not correct.

The second issue potentially existed all along, but it's a littlie easier
to hit now: we need to lock out shutdown from manipulating registers
while they're being setup. This was hit by forcing controller reset from
the shelll in a loop, then "rmmod nvme" at the same time.