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>
diff --git a/drivers/net/bonding/bond_procfs.c b/drivers/net/bonding/bond_procfs.c
index 3cea38d..94d06f1 100644
--- a/drivers/net/bonding/bond_procfs.c
+++ b/drivers/net/bonding/bond_procfs.c
@@ -218,15 +218,13 @@
 static int bond_info_open(struct inode *inode, struct file *file)
 {
 	struct seq_file *seq;
-	struct proc_dir_entry *proc;
 	int res;
 
 	res = seq_open(file, &bond_info_seq_ops);
 	if (!res) {
 		/* recover the pointer buried in proc_dir_entry data */
 		seq = file->private_data;
-		proc = PDE(inode);
-		seq->private = proc->data;
+		seq->private = PDE_DATA(inode);
 	}
 
 	return res;