udf: remove duplicated #include

Remove duplicated #include('s) in
  fs/udf/file.c
Signed-off-by: NHuang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: NJan Kara <jack@suse.cz>

fs/udf/file.c

@@ -36,7 +36,6 @@
 #include <linux/pagemap.h>
 #include <linux/buffer_head.h>
 #include <linux/aio.h>
-#include <linux/smp_lock.h>
 
 #include "udf_i.h"
 #include "udf_sb.h"