x86 mmiotrace: page level is unsigned

Fixes some sparse warnings.

Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c
index ed0e0e9..e7397e1 100644
--- a/arch/x86/mm/mmio-mod.c
+++ b/arch/x86/mm/mmio-mod.c
@@ -137,7 +137,7 @@
 
 static void print_pte(unsigned long address)
 {
-	int level;
+	unsigned int level;
 	pte_t *pte = lookup_address(address, &level);
 
 	if (!pte) {