Add ERROR_LOG for Illegal Priority

Core/HLE/sceIo.cpp

@@ -1527,6 +1527,7 @@ u32 sceIoChdir(const char *dirname) {
 int sceIoChangeAsyncPriority(int id, int priority)
 {
 	if (priority < 0) {
+		ERROR_LOG(SCEIO, "sceIoChangeAsyncPriority : Illegal Priority")
 		return SCE_KERNEL_ERROR_ILLEGAL_PRIORITY;
 	}
 	ERROR_LOG(SCEIO, "UNIMPL sceIoChangeAsyncPriority(%d, %d)", id, priority);