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/block/DAC960.c b/drivers/block/DAC960.c
index 5b5ee79..eb39501 100644
--- a/drivers/block/DAC960.c
+++ b/drivers/block/DAC960.c
@@ -6473,7 +6473,7 @@
 
 static int dac960_initial_status_proc_open(struct inode *inode, struct file *file)
 {
-	return single_open(file, dac960_initial_status_proc_show, PDE(inode)->data);
+	return single_open(file, dac960_initial_status_proc_show, PDE_DATA(inode));
 }
 
 static const struct file_operations dac960_initial_status_proc_fops = {
@@ -6519,7 +6519,7 @@
 
 static int dac960_current_status_proc_open(struct inode *inode, struct file *file)
 {
-	return single_open(file, dac960_current_status_proc_show, PDE(inode)->data);
+	return single_open(file, dac960_current_status_proc_show, PDE_DATA(inode));
 }
 
 static const struct file_operations dac960_current_status_proc_fops = {
@@ -6540,14 +6540,14 @@
 
 static int dac960_user_command_proc_open(struct inode *inode, struct file *file)
 {
-	return single_open(file, dac960_user_command_proc_show, PDE(inode)->data);
+	return single_open(file, dac960_user_command_proc_show, PDE_DATA(inode));
 }
 
 static ssize_t dac960_user_command_proc_write(struct file *file,
 				       const char __user *Buffer,
 				       size_t Count, loff_t *pos)
 {
-  DAC960_Controller_T *Controller = (DAC960_Controller_T *) PDE(file_inode(file))->data;
+  DAC960_Controller_T *Controller = PDE_DATA(file_inode(file));
   unsigned char CommandBuffer[80];
   int Length;
   if (Count > sizeof(CommandBuffer)-1) return -EINVAL;