Take the completion of automount into new helper

... and shift it from namei.c to namespace.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/internal.h b/fs/internal.h
index 12ccb86..e8a0b24 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -70,6 +70,7 @@
 extern void release_mounts(struct list_head *);
 extern void umount_tree(struct vfsmount *, int, struct list_head *);
 extern struct vfsmount *copy_tree(struct vfsmount *, struct dentry *, int);
+extern int finish_automount(struct vfsmount *, struct path *);
 extern int do_add_mount(struct vfsmount *, struct path *, int);
 extern void mnt_clear_expiry(struct vfsmount *);