NFS: remove duplicated include from nfs4file.c

Remove duplicated include.

Signed-off-by: YueHaibing <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>

Author: YueHaibing

fs/nfs/nfs4file.c

@@ -8,7 +8,6 @@
 #include <linux/file.h>
 #include <linux/falloc.h>
 #include <linux/nfs_fs.h>
-#include <linux/file.h>
 #include "delegation.h"
 #include "internal.h"
 #include "iostat.h"