fsnotify: store struct file not struct path

Al explains that calling dentry_open() with a mnt/dentry pair is only
garunteed to be safe if they are already used in an open struct file.  To
make sure this is the case don't store and use a struct path in fsnotify,
always use a struct file.

Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index 7499397..b955a22 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -545,8 +545,8 @@
 		return 0;
 
 	switch (event->data_type) {
-	case (FSNOTIFY_EVENT_PATH):
-		inode = event->path.dentry->d_inode;
+	case (FSNOTIFY_EVENT_FILE):
+		inode = event->file->f_path.dentry->d_inode;
 		break;
 	case (FSNOTIFY_EVENT_INODE):
 		inode = event->inode;