If the controller is failed, attempting to submit additional I/O is
futile - it will be immediately failed using the completion callback,
which can result in infinite recursion if the application code resubmits
I/Os on failure.
Instead, provide a way for request submission to indicate failure, and
use it to exit early if the controller is failed; this can only happen
when a reset failed (timed out).
If a request is submitted directly by the user when the controller has
failed, we can return an error code directly. For the case where I/O
was queued and is being resubmitted after a reset, we still need to call
the completion handler via _nvme_fail_request_ctrlr_failed().
Change-Id: I9e144328d524b25db2acf48e923b584746e8d0b6
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>