fixed some code warnings

src/akiru/src/akiru.cpp

@@ -37,7 +37,7 @@
 
 /// Application entry point
 int __cdecl main(int argc, char **argv) {
-    u32 tight_loop;
+    //u32 tight_loop;
 
     printf("akiru starting...\n");
 

src/common/src/file_util.cpp

@@ -781,7 +781,7 @@ bool ReadFileToString(bool text_file, const char *filename, std::string &str)
 	if (!f)
 		return false;
 
-	str.resize(GetSize(f));
+	str.resize(static_cast<u32>(GetSize(f)));
 	return file.ReadArray(&str[0], str.size());
 }