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/sbs.c b/drivers/acpi/sbs.c
index e523245..a296e08 100644
--- a/drivers/acpi/sbs.c
+++ b/drivers/acpi/sbs.c
@@ -584,7 +584,7 @@
 
 static int acpi_battery_info_open_fs(struct inode *inode, struct file *file)
 {
-	return single_open(file, acpi_battery_read_info, PDE(inode)->data);
+	return single_open(file, acpi_battery_read_info, PDE_DATA(inode));
 }
 
 static int acpi_battery_read_state(struct seq_file *seq, void *offset)
@@ -623,7 +623,7 @@
 
 static int acpi_battery_state_open_fs(struct inode *inode, struct file *file)
 {
-	return single_open(file, acpi_battery_read_state, PDE(inode)->data);
+	return single_open(file, acpi_battery_read_state, PDE_DATA(inode));
 }
 
 static int acpi_battery_read_alarm(struct seq_file *seq, void *offset)
@@ -688,7 +688,7 @@
 
 static int acpi_battery_alarm_open_fs(struct inode *inode, struct file *file)
 {
-	return single_open(file, acpi_battery_read_alarm, PDE(inode)->data);
+	return single_open(file, acpi_battery_read_alarm, PDE_DATA(inode));
 }
 
 static const struct file_operations acpi_battery_info_fops = {
@@ -736,7 +736,7 @@
 
 static int acpi_ac_state_open_fs(struct inode *inode, struct file *file)
 {
-	return single_open(file, acpi_ac_read_state, PDE(inode)->data);
+	return single_open(file, acpi_ac_read_state, PDE_DATA(inode));
 }
 
 static const struct file_operations acpi_ac_state_fops = {