[XAM/User] Only set buffer_size if it's too small

CoD4 calls this with a huge 0x4000 buffer, and then if the buffer_size returned is any smaller it asserts & stops running...
Need to check if this is actually how it should work, but this should help get some CoD4 running

src/xenia/kernel/xam/xam_user.cc

@@ -286,7 +286,9 @@ dword_result_t XamUserReadProfileSettings(
   }
 
   uint32_t buffer_size = static_cast<uint32_t>(*buffer_size_ptr);
+  if (buffer_size < size_needed) {
     *buffer_size_ptr = size_needed;
+  }
 
   if (!buffer_ptr || buffer_size < size_needed) {
     if (overlapped_ptr) {