oprofile: make event buffer nonseekable

The event buffer cannot deal with seeks, so
we should forbid that outright.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Robert Richter <robert.richter@amd.com>
Cc: oprofile-list@lists.sf.net
Signed-off-by: Robert Richter <robert.richter@amd.com>

drivers/oprofile/event_buffer.c

@@ -135,7 +135,7 @@ static int event_buffer_open(struct inode *inode, struct file *file)
 	 * echo 1 >/dev/oprofile/enable
 	 */
 
-	return 0;
+	return nonseekable_open(inode, file);
 
 fail:
 	dcookie_unregister(file->private_data);
@@ -205,4 +205,5 @@ const struct file_operations event_buffer_fops = {
 	.open		= event_buffer_open,
 	.release	= event_buffer_release,
 	.read		= event_buffer_read,
+	.llseek		= no_llseek,
 };