Fix for discovery failure in PT2PT when FLOGI's ELS ACC response gets aborted

Change login state machine to:
- Restart FLOGI if prior is ABTS'd
- Reject incoming FLOGIs if we have one pending

The above ensures that we always finish FLOGI processing, regardless
of who initated FLOGI, before processing PLOGI's.
Signed-off-by: Dick Kennedy <dick.kennedy@avagotech.com>
Signed-off-by: James Smart <james.smart@avagotech.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>