scsi: qla2xxx: Ignore PORT UPDATE after N2N PLOGI

PORT UPDATE asynchronous event is generated on the host that issues PLOGI
ELS (in the case of higher WWPN). In that case, the event shouldn't be
handled as it sets unwanted DPC flags (i.e. LOOP_RESYNC_NEEDED) that
trigger link flap.

Ignore the event if the host has higher WWPN, but handle otherwise.

Cc: Quinn Tran <qutran@marvell.com>
Link: https://lore.kernel.org/r/20191125165702.1013-13-r.bolshakov@yadro.com


Acked-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>