inotify: don't leak user struct on inotify release

inotify_new_group() receives a get_uid-ed user_struct and saves the
reference on group->inotify_data.user.  The problem is that free_uid() is
never called on it.

Issue seem to be introduced by 63c882a0 (inotify: reimplement inotify
using fsnotify) after 2.6.30.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Eric Paris <eparis@parisplace.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Eric Paris <eparis@redhat.com>

fs/notify/inotify/inotify_fsnotify.c

@@ -28,6 +28,7 @@
 #include <linux/path.h> /* struct path */
 #include <linux/slab.h> /* kmem_* */
 #include <linux/types.h>
+#include <linux/sched.h>
 
 #include "inotify.h"
 
@@ -146,6 +147,7 @@ static void inotify_free_group_priv(struct fsnotify_group *group)
 	idr_for_each(&group->inotify_data.idr, idr_callback, group);
 	idr_remove_all(&group->inotify_data.idr);
 	idr_destroy(&group->inotify_data.idr);
+	free_uid(group->inotify_data.user);
 }
 
 void inotify_free_event_priv(struct fsnotify_event_private_data *fsn_event_priv)