nvme: Fix backwards sense of error condition

b21e67875bf0c tested for the good condition, not the error condition, so
we'd never do anything else in this function. This was causing certain
logging not to happen, and also prevented forthcoming namespace size
change code from working as well.

Fixes: b21e67875bf0c
Sponsored by: Netflix
(cherry picked from commit 27481c268916b0790c7ad16202a5b012625ce1a8)