x86: fixes for lookup_address args

Signedness mismatches in level argument.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/efi_64.c b/arch/x86/kernel/efi_64.c
index 4b73992..674f237 100644
--- a/arch/x86/kernel/efi_64.c
+++ b/arch/x86/kernel/efi_64.c
@@ -44,7 +44,7 @@
 					  int executable)
 {
 	pte_t *kpte;
-	int level;
+	unsigned int level;
 
 	while (start < end) {
 		kpte = lookup_address((unsigned long)__va(start), &level);