[SCSI] fnic: Kernel panic while running sh/nosh with max lun cfg

Kernel panics due to NULL lport while executing the log message because
of synchronization issues between libfc and scsi transport fc. Checking
for NULL pointers at the beginning of this routine would resolve the issue
from kernel panic point of view.

Signed-off-by: Sesidhar Baddel <sebaddel@cisco.com>
Signed-off-by: Hiral Patel <hiralpat@cisco.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>