proc: add a proc_create_reg helper

Common code for creating a regular file.  Factor out of proc_create_data, to
be reused by other functions soon.

Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 488e674..dd1e114 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -162,6 +162,8 @@ extern bool proc_fill_cache(struct file *, struct dir_context *, const char *, i
 /*
  * generic.c
  */
+struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,
+		struct proc_dir_entry **parent, void *data);
 struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
 		struct proc_dir_entry *dp);
 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);