Revert "[PATCH] namespaces: fix exit race by splitting exit"

This reverts commit 7a238fcba0629b6f2edbcd37458bae56fcf36be5 in
preparation for a better and simpler fix proposed by Eric Biederman
(and fixed up by Serge Hallyn)

Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/exit.c b/kernel/exit.c
index a5bf532..3540172 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -396,7 +396,7 @@
 	current->fs = fs;
 	atomic_inc(&fs->count);
 
-	put_and_finalize_nsproxy(current->nsproxy);
+	exit_task_namespaces(current);
 	current->nsproxy = init_task.nsproxy;
 	get_task_namespaces(current);
 
@@ -853,7 +853,6 @@
 fastcall NORET_TYPE void do_exit(long code)
 {
 	struct task_struct *tsk = current;
-	struct nsproxy *ns;
 	int group_dead;
 
 	profile_task_exit(tsk);
@@ -939,9 +938,8 @@
 
 	tsk->exit_code = code;
 	proc_exit_connector(tsk);
-	ns = preexit_task_namespaces(tsk);
 	exit_notify(tsk);
-	exit_task_namespaces(tsk, ns);
+	exit_task_namespaces(tsk);
 #ifdef CONFIG_NUMA
 	mpol_free(tsk->mempolicy);
 	tsk->mempolicy = NULL;