mptcp: use nlmsg_free instead of kfree_skb

Use nlmsg_free() instead of kfree_skb() in pm_netlink.c.

The SKB's have been created by nlmsg_new(). The proper cleaning way
should then be done with nlmsg_free().

For the moment, nlmsg_free() is simply calling kfree_skb() so we don't
change the behaviour here.
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/mptcp/pm_netlink.c

@@ -2094,7 +2094,7 @@ void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id)
 	return;
 
 nla_put_failure:
-	kfree_skb(skb);
+	nlmsg_free(skb);
 }
 
 void mptcp_event_addr_announced(const struct sock *ssk,
@@ -2151,7 +2151,7 @@ void mptcp_event_addr_announced(const struct sock *ssk,
 	return;
 
 nla_put_failure:
-	kfree_skb(skb);
+	nlmsg_free(skb);
 }
 
 void mptcp_event_pm_listener(const struct sock *ssk,
@@ -2203,7 +2203,7 @@ void mptcp_event_pm_listener(const struct sock *ssk,
 	return;
 
 nla_put_failure:
-	kfree_skb(skb);
+	nlmsg_free(skb);
 }
 
 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
@@ -2261,7 +2261,7 @@ void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
 	return;
 
 nla_put_failure:
-	kfree_skb(skb);
+	nlmsg_free(skb);
 }
 
 static const struct genl_small_ops mptcp_pm_ops[] = {