NFS: Move nfs_idmap.h into fs/nfs/

This file is only used internally to the NFS v4 module, so it doesn't
need to be in the global include path.  I also renamed it from
nfs_idmap.h to nfs4idmap.h to emphasize that it's an NFSv4-only include
file.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/nfs4sysctl.c

@@ -6,10 +6,10 @@
  * Copyright (c) 2006 Trond Myklebust <Trond.Myklebust@netapp.com>
  */
 #include <linux/sysctl.h>
-#include <linux/nfs_idmap.h>
 #include <linux/nfs_fs.h>
 
 #include "nfs4_fs.h"
+#include "nfs4idmap.h"
 #include "callback.h"
 
 static const int nfs_set_port_min = 0;