net: Fix build with INET disabled.

> net/core/sock.c: In function 'sk_update_clone':
> net/core/sock.c:1278:3: error: implicit declaration of function 'sock_update_memcg'

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/memcontrol.h

@@ -390,7 +390,6 @@ enum {
 	OVER_LIMIT,
 };
 
-#ifdef CONFIG_INET
 struct sock;
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
 void sock_update_memcg(struct sock *sk);
@@ -403,6 +402,5 @@ static inline void sock_release_memcg(struct sock *sk)
 {
 }
 #endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
-#endif /* CONFIG_INET */
 #endif /* _LINUX_MEMCONTROL_H */
 

net/core/sock.c

@@ -112,6 +112,7 @@
 #include <linux/highmem.h>
 #include <linux/user_namespace.h>
 #include <linux/jump_label.h>
+#include <linux/memcontrol.h>
 
 #include <asm/uaccess.h>
 #include <asm/system.h>