nvme_fc: fix error recovery on link down.

Currently, the fc transport invokes nvme_fc_error_recovery() on every
io in which the transport detects an error.  Which means:
a) it's really noisy on large io loads that all get hit by a link down.
b) we repeatively call nvme_stop_queues() even though queues are
 stopped upon the first error or as first steps of reset_work.

Correct by:
Errors are only meaningful if the controller is in the LIVE state.
Thus, enact the reset_work only if LIVE. If called repeatively, state
will have already transitioned.
There's no need to stop the queues here. Let the first steps of
reset_work do the queue stopping.

Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>