headers_check fix: nfsd/export.h

fix the following 'make headers_check' warning:

  usr/include/linux/nfsd/export.h:13: include of <linux/types.h> is preferred over <asm/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

include/linux/nfsd/export.h

@@ -10,9 +10,8 @@
 #ifndef NFSD_EXPORT_H
 #define NFSD_EXPORT_H
 
-#include <asm/types.h>
-#ifdef __KERNEL__
 # include <linux/types.h>
+#ifdef __KERNEL__
 # include <linux/in.h>
 #endif