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/scsi/scsi_proc.c b/drivers/scsi/scsi_proc.c
index 1eb34c3..db66357 100644
--- a/drivers/scsi/scsi_proc.c
+++ b/drivers/scsi/scsi_proc.c
@@ -48,7 +48,7 @@
 static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf,
                            size_t count, loff_t *ppos)
 {
-	struct Scsi_Host *shost = PDE(file_inode(file))->data;
+	struct Scsi_Host *shost = PDE_DATA(file_inode(file));
 	ssize_t ret = -ENOMEM;
 	char *page;
     
@@ -78,7 +78,7 @@
 
 static int proc_scsi_host_open(struct inode *inode, struct file *file)
 {
-	return single_open_size(file, proc_scsi_show, PDE(inode)->data,
+	return single_open_size(file, proc_scsi_show, PDE_DATA(inode),
 				4 * PAGE_SIZE);
 }