xen: balloon: use correct type for frame_list

This is now a xen_pfn_t.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index d7bd1b3..d6886d9 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -87,7 +87,7 @@
 EXPORT_SYMBOL_GPL(balloon_stats);
 
 /* We increase/decrease in batches which fit in a page */
-static unsigned long frame_list[PAGE_SIZE / sizeof(unsigned long)];
+static xen_pfn_t frame_list[PAGE_SIZE / sizeof(unsigned long)];
 
 #ifdef CONFIG_HIGHMEM
 #define inc_totalhigh_pages() (totalhigh_pages++)