vedit: define structs in render.c as static

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@44824 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/vector/vedit/render.c

@@ -15,7 +15,7 @@
 
 #include <grass/vedit.h>
 
-struct _region
+static struct _region
 {
     double center_easting;
     double center_northing;
@@ -26,7 +26,7 @@ struct _region
     double map_res;
 } region;
 
-struct _state
+static struct _state
 {
     int nitems_alloc;