Replace int types in Retro code

Retro seemingly avoided using the Dolphin
typedefs in most places, opting to use int/uint
instead. This likely means they didn't use
u8/s8/u16/s16/etc either.

src/Collision/CMaterialList.cpp

@@ -1,6 +1,6 @@
 #include "Collision/CMaterialList.hpp"
 
-s32 CMaterialList::BitPosition(u64 flags) {
+int CMaterialList::BitPosition(u64 flags) {
   for (int ret = 0, i = 0; i < 32; ++i) {
     if ((flags & 1) != 0) {
       return ret;