Fix building with PCH disabled.

Source/Core/Core/IPC_HLE/WII_IPC_HLE_Device_fs.cpp

@@ -2,6 +2,8 @@
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
 
+#include <algorithm>
+
 #include "Common/ChunkFile.h"
 #include "Common/CommonPaths.h"
 #include "Common/CommonTypes.h"