proc: consolidate per-net single-release callers

They are symmetrical to single_open ones :)

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/seq_file_net.h b/include/linux/seq_file_net.h
index 87dcc0e..32c89bb 100644
--- a/include/linux/seq_file_net.h
+++ b/include/linux/seq_file_net.h
@@ -17,6 +17,7 @@
 int single_open_net(struct inode *, struct file *file,
 		int (*show)(struct seq_file *, void *));
 int seq_release_net(struct inode *, struct file *);
+int single_release_net(struct inode *, struct file *);
 static inline struct net *seq_file_net(struct seq_file *seq)
 {
 #ifdef CONFIG_NET_NS