r.composite use standardized options (https://trac.osgeo.org/grass/ticket/2409)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@62999 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.composite/main.c

@@ -108,7 +108,7 @@ int main(int argc, char **argv)
 
 	B[i].opt_levels = opt = G_define_option();
 
-	sprintf(buff, "lev_%s", color_names[i]);
+	sprintf(buff, "level_%s", color_names[i]);
 	opt->key = G_store(buff);
 
 	opt->type = TYPE_INTEGER;