[PATCH] mremap offset type

Just found I never changed type of move_page_tables when I changed it to
return offset: einormous mremap moves would fail on 64-bit.

mm/mremap.c

@@ -145,7 +145,7 @@ move_one_page(struct vm_area_struct *vma, unsigned long old_addr,
 	return error;
 }
 
-static int move_page_tables(struct vm_area_struct *vma,
+static unsigned long move_page_tables(struct vm_area_struct *vma,
 	unsigned long new_addr, unsigned long old_addr, unsigned long len)
 {
 	unsigned long offset;