net: include linux/proc_fs.h in dev_addr_lists.c

As pointed by Randy Dunlap, we must include linux/proc_fs.h in
net/core/dev_addr_lists.c, regardless of CONFIG_PROC_FS

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>, 
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev_addr_lists.c

@@ -14,6 +14,7 @@
 #include <linux/netdevice.h>
 #include <linux/rtnetlink.h>
 #include <linux/list.h>
+#include <linux/proc_fs.h>
 
 /*
  * General list handling functions
@@ -667,7 +668,6 @@ void dev_mc_init(struct net_device *dev)
 EXPORT_SYMBOL(dev_mc_init);
 
 #ifdef CONFIG_PROC_FS
-#include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 
 static int dev_mc_seq_show(struct seq_file *seq, void *v)