By default clang16 will not allow implicit integer declarations in function parameters.

Bug: https://bugs.gentoo.org/874891

Signed-off-by: Pascal Jäger <pascal.jaeger@leimstift.de>
--- a/gkrellshoot.c
+++ b/gkrellshoot.c
@@ -436,7 +436,7 @@ double star_screenx[NUM_STARS];
 double star_screeny[NUM_STARS];
 
 static void
-draw_starfield ( chart_index )
+draw_starfield ( size_t  chart_index )
 {
   gint i;
   guchar b;
-- 
2.38.1