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/acpi/proc.c b/drivers/acpi/proc.c
index 52ce767..aa1227a 100644
--- a/drivers/acpi/proc.c
+++ b/drivers/acpi/proc.c
@@ -120,7 +120,7 @@
 
 static int acpi_system_alarm_open_fs(struct inode *inode, struct file *file)
 {
-	return single_open(file, acpi_system_alarm_seq_show, PDE(inode)->data);
+	return single_open(file, acpi_system_alarm_seq_show, PDE_DATA(inode));
 }
 
 static int get_date_field(char **p, u32 * value)
@@ -397,7 +397,7 @@
 acpi_system_wakeup_device_open_fs(struct inode *inode, struct file *file)
 {
 	return single_open(file, acpi_system_wakeup_device_seq_show,
-			   PDE(inode)->data);
+			   PDE_DATA(inode));
 }
 
 static const struct file_operations acpi_system_wakeup_device_fops = {