NVMe: Namespace removal simplifications
NVMe: Namespace removal simplifications

This liberates namespace removal from the device, allowing gendisk
references to be closed independent of the nvme controller reference
count.

Signed-off-by: Keith Busch <695e2a2c1e39535baaa147c5eb4e5da14054d59f@intel.com>
Reviewed-by: Christoph Hellwig <923f7720577207a44b32e59bbfbea59d27f1ae8e@lst.de>
Signed-off-by: Jens Axboe <cd8c6775e60d6f67a6984377324e5290df3d5358@fb.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs