scsi: qla2xxx: Fix unintended Logout

During normal IO, FW can return IO with 'port unavailble' status.  Driver
would send a LOGO to remote port for session resync.  On an off chance, a
PLOGI could arrive before sending the LOGO.  This patch will skip sendiing
LOGO if a PLOGI just came in.

Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>