proc: introduce proc_create_net_single

Variant of proc_create_data that directly take a seq_file show
callback and deals with network namespaces in ->open and ->release.
All callers of proc_create + single_open_net converted over, and
single_{open,release}_net are removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/include/linux/seq_file_net.h b/include/linux/seq_file_net.h
index 5ea18a1..0fdbe1d 100644
--- a/include/linux/seq_file_net.h
+++ b/include/linux/seq_file_net.h
@@ -13,9 +13,6 @@ struct seq_net_private {
 #endif
 };
 
-int single_open_net(struct inode *, struct file *file,
-		int (*show)(struct seq_file *, void *));
-int single_release_net(struct inode *, struct file *);
 static inline struct net *seq_file_net(struct seq_file *seq)
 {
 #ifdef CONFIG_NET_NS
@@ -26,8 +23,8 @@ static inline struct net *seq_file_net(struct seq_file *seq)
 }
 
 /*
- * This one is needed for single_open_net since net is stored directly in
- * private not as a struct i.e. seq_file_net can't be used.
+ * This one is needed for proc_create_net_single since net is stored directly
+ * in private not as a struct i.e. seq_file_net can't be used.
  */
 static inline struct net *seq_file_single_net(struct seq_file *seq)
 {