net/sock: Add sock_efree() function

Extracted from commit 62bccb8c ("net-timestamp: Make the clone operation
stand-alone from phy timestamping").
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

include/net/sock.h

@@ -1117,6 +1117,7 @@ extern struct sk_buff		*sock_rmalloc(struct sock *sk,
 					      gfp_t priority);
 extern void			sock_wfree(struct sk_buff *skb);
 extern void			sock_rfree(struct sk_buff *skb);
+void sock_efree(struct sk_buff *skb);
 
 extern int			sock_setsockopt(struct socket *sock, int level,
 						int op, char __user *optval,

net/core/sock.c

@@ -1369,6 +1369,11 @@ void sock_rfree(struct sk_buff *skb)
 }
 EXPORT_SYMBOL(sock_rfree);
 
+void sock_efree(struct sk_buff *skb)
+{
+	sock_put(skb->sk);
+}
+EXPORT_SYMBOL(sock_efree);
 
 int sock_i_uid(struct sock *sk)
 {