procfs: new helper - PDE_DATA(inode)

The only part of proc_dir_entry the code outside of fs/proc
really cares about is PDE(inode)->data.  Provide a helper
for that; static inline for now, eventually will be moved
to fs/proc, along with the knowledge of struct proc_dir_entry
layout.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/isdn/hysdn/hycapi.c

@@ -469,7 +469,7 @@ static int hycapi_proc_show(struct seq_file *m, void *v)
 
 static int hycapi_proc_open(struct inode *inode, struct file *file)
 {
-	return single_open(file, hycapi_proc_show, PDE(inode)->data);
+	return single_open(file, hycapi_proc_show, PDE_DATA(inode));
 }
 
 static const struct file_operations hycapi_proc_fops = {