scsi: qla2xxx: Fix possible fcport null-pointer dereferences

In qla2x00_alloc_fcport(), fcport is assigned to NULL in the error
handling code on line 4880:
    fcport = NULL;

Then fcport is used on lines 4883-4886:
    INIT_WORK(&fcport->del_work, qla24xx_delete_sess_fn);
	INIT_WORK(&fcport->reg_work, qla_register_fcport_fn);
	INIT_LIST_HEAD(&fcport->gnl_entry);
	INIT_LIST_HEAD(&fcport->list);

Thus, possible null-pointer dereferences may occur.

To fix these bugs, qla2x00_alloc_fcport() directly returns NULL
in the error handling code.

These bugs are found by a static analysis tool STCheck written by us.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Acked-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_init.c

@@ -4877,7 +4877,7 @@ qla2x00_alloc_fcport(scsi_qla_host_t *vha, gfp_t flags)
 		ql_log(ql_log_warn, vha, 0xd049,
 		    "Failed to allocate ct_sns request.\n");
 		kfree(fcport);
-		fcport = NULL;
+		return NULL;
 	}
 
 	INIT_WORK(&fcport->del_work, qla24xx_delete_sess_fn);