[IA64] BUG to BUG_ON changes

Replace:

	if (test)
		BUG();

with
	BUG_ON(test);

Signed-off-by: Stoyan Gaydarov <stoyboyker@gmail.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 8503d53..c0f3bee 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -636,8 +636,7 @@
 #endif
 
 #ifdef CONFIG_FLATMEM
-	if (!mem_map)
-		BUG();
+	BUG_ON(!mem_map);
 	max_mapnr = max_low_pfn;
 #endif