rocker: fix memory leak in rocker_world_port_post_fini()

In rocker_world_port_pre_init(), rocker_port->wpriv is allocated with
kzalloc(wops->port_priv_size, GFP_KERNEL). However, in
rocker_world_port_post_fini(), the memory is only freed when
wops->port_post_fini callback is set:

if (!wops->port_post_fini)
return;
wops->port_post_fini(rocker_port);
kfree(rocker_port->wpriv);

Since rocker_ofdpa_ops does not implement port_post_fini callback
(it is NULL), the wpriv memory allocated for each port is never freed
when ports are removed. This leads to a memory leak of
sizeof(struct ofdpa_port) bytes per port on every device removal.

Fix this by always calling kfree(rocker_port->wpriv) regardless of
whether the port_post_fini callback exists.

Fixes: e420114eef4a ("rocker: introduce worlds infrastructure")
Signed-off-by: Kery Qi <[e-mail]>
Reviewed-by: Simon Horman <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/ethernet/rocker/rocker_main.c

···
 {
 	struct rocker_world_ops *wops = rocker_port->rocker->wops;
 
-	if (!wops->port_post_fini)
-		return;
-	wops->port_post_fini(rocker_port);
+	if (wops->port_post_fini)
+		wops->port_post_fini(rocker_port);
 	kfree(rocker_port->wpriv);
 }