scsi: libfc: directly call ELS request handlers

Directly call ELS request handler functions in fc_lport_recv_els_req
instead of saving the pointer to the handler's receive function and then
later dereferencing this pointer.

This makes the code a bit more obvious.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Chad Dupuis <chad.dupuis@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>