When receiving an unsolicited frame we could crash on a list traversal in
fc_rport_lookup while searching the rport which is associated with our
lport.

Initialize the lport's discovery node after allocating the lport in
__qedf_probe().
Signed-off-by: Chad Dupuis <cdupuis@marvell.com>
Signed-off-by: Saurav Kashyap <skashyap@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>