fix memory leak in xloadcols()

reported by Avi Halachmi (:avih)" <avihpit@yahoo.com>

patch slightly changed by me.

x.c

@@ -733,12 +733,12 @@ xloadcols(void)
 	static int loaded;
 	Color *cp;
 
-	dc.collen = MAX(LEN(colorname), 256);
-	dc.col = xmalloc(dc.collen * sizeof(Color));
-
 	if (loaded) {
 		for (cp = dc.col; cp < &dc.col[dc.collen]; ++cp)
 			XftColorFree(xw.dpy, xw.vis, xw.cmap, cp);
+	} else {
+		dc.collen = MAX(LEN(colorname), 256);
+		dc.col = xmalloc(dc.collen * sizeof(Color));
 	}
 
 	for (i = 0; i < dc.collen; i++)