headers: mnt_namespace.h redux

Fix various silly problems wrt mnt_namespace.h:

 - exit_mnt_ns() isn't used, remove it
 - done that, sched.h and nsproxy.h inclusions aren't needed
 - mount.h inclusion was need for vfsmount_lock, but no longer
 - remove mnt_namespace.h inclusion from files which don't use anything
   from mnt_namespace.h

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mnt_namespace.h b/include/linux/mnt_namespace.h
index 3beb259..d74785c 100644
--- a/include/linux/mnt_namespace.h
+++ b/include/linux/mnt_namespace.h
@@ -2,10 +2,9 @@
 #define _NAMESPACE_H_
 #ifdef __KERNEL__
 
-#include <linux/mount.h>
-#include <linux/sched.h>
-#include <linux/nsproxy.h>
+#include <linux/path.h>
 #include <linux/seq_file.h>
+#include <linux/wait.h>
 
 struct mnt_namespace {
 	atomic_t		count;
@@ -28,14 +27,6 @@
 extern struct mnt_namespace *copy_mnt_ns(unsigned long, struct mnt_namespace *,
 		struct fs_struct *);
 extern void put_mnt_ns(struct mnt_namespace *ns);
-
-static inline void exit_mnt_ns(struct task_struct *p)
-{
-	struct mnt_namespace *ns = p->nsproxy->mnt_ns;
-	if (ns)
-		put_mnt_ns(ns);
-}
-
 static inline void get_mnt_ns(struct mnt_namespace *ns)
 {
 	atomic_inc(&ns->count);