crtools: include list.h in vma.h

This patch fixes compilation error on arm:
In file included from arch/arm/vdso-pie.c:4:0:
include/vma.h:5:19: error: field ‘h’ has incomplete type
include/vma.h:14:19: error: field ‘list’ has incomplete type
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/vma.h

 #ifndef __CR_VMA_H__
 #define __CR_VMA_H__
 
+#include "list.h"
+
 struct vm_area_list {
 	struct list_head	h;
 	unsigned		nr;