Remove unnecessary typedef

This should also fix compiling-errors on OpenBSD,
as reported by Nils R. Thanks!

Signed-off-by: Roberto E. Vargas Caballero <k0ga@shike2.com>

st.c

@@ -180,7 +180,6 @@ typedef unsigned short ushort;
 
 typedef XftDraw *Draw;
 typedef XftColor Color;
-typedef Colormap Colormap;
 
 typedef struct {
 	char c[UTF_SIZ]; /* character code */