NFS: build fixed in case of NFS_USE_NEW_IDMAPPER is undefined

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/idmap.c

@@ -62,6 +62,7 @@
 #include <linux/nfs_fs.h>
 #include "nfs4_fs.h"
 #include "internal.h"
+#include "netns.h"
 
 #define NFS_UINT_MAXLEN 11
 #define IDMAP_HASH_SZ          128