Use min/max instead of MIN/MAX.

diff --git a/windows/user.c b/windows/user.c
index c8b3f6b..7d4a735 100644
--- a/windows/user.c
+++ b/windows/user.c
@@ -69,7 +69,7 @@
     default:
         return 0;
     }
-    return (WORD)MIN( userPercent, gdiPercent );
+    return (WORD)min( userPercent, gdiPercent );
 }