fix errors

kernel/memory/pageframealloc.cc

@@ -1,5 +1,4 @@
 #include "../memory/pageframealloc.h"
-#include <cstdint>
 #include "pageframe.h"
 
 void PageFrameAllocator::init(){
@@ -9,11 +8,14 @@ void PageFrameAllocator::stats(){
 }
 
 PageFrame* PageFrameAllocator::alloc(bool kernel){
+    (void) kernel;
     return 0;
 }
 
 void PageFrameAllocator::free(PageFrame* frame){
+    (void) frame;
 }
 
 void PageFrameAllocator::free(uintptr_t addr){
+    (void) addr;
 }