scsi: qla2xxx: Fix LUN discovery if loop id is not assigned yet by firmware

This patch fixes LUN discovery when loop ID is not yet assigned by the
firmware during driver load/sg_reset operations. Driver will now search for
new loop id before retrying login.

Fixes: 48acad09 ("scsi: qla2xxx: Fix N2N link re-connect")
Cc: stable@vger.kernel.org #4.19
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>