netlink: Deletion of an unnecessary check before the function call "__module_get"

The __module_get() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netlink/af_netlink.c

@@ -142,8 +142,7 @@ int netlink_add_tap(struct netlink_tap *nt)
 	list_add_rcu(&nt->list, &netlink_tap_all);
 	spin_unlock(&netlink_tap_lock);
 
-	if (nt->module)
-		__module_get(nt->module);
+	__module_get(nt->module);
 
 	return 0;
 }