NVMe: fix error return checking from blk_mq_alloc_request()
NVMe: fix error return checking from blk_mq_alloc_request()

We return an error pointer or the request, not NULL. Half
the call paths got it right, the others didn't. Fix those up.

Signed-off-by: Jens Axboe <cd8c6775e60d6f67a6984377324e5290df3d5358@fb.com>

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