x86: ioremap, remove WARN_ON()

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index ac3c959..8fe576b 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -134,8 +134,6 @@
 			return NULL;
 	}
 
-	WARN_ON_ONCE(page_is_ram(pfn));
-
 	switch (mode) {
 	case IOR_MODE_UNCACHED:
 	default: