[gimp] plug-ins: fix some more cast of different size warnings.

[Jehan <jehanp src gnome org>]

commit 0567bb2e719be7ea22ebd3d0e8f66e6dd8df48ac
Author: Jehan <jehan girinstud io>
Date:   Sun Sep 22 14:20:02 2019 +0200

    plug-ins: fix some more cast of different size warnings.
    
    Use GINT_TO_POINTER() and GPOINTER_TO_INT() on GList functions.

 plug-ins/gimpressionist/repaint.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/plug-ins/gimpressionist/repaint.c b/plug-ins/gimpressionist/repaint.c
index c8eba2d18a..6a985c183e 100644
--- a/plug-ins/gimpressionist/repaint.c
+++ b/plug-ins/gimpressionist/repaint.c
@@ -205,7 +205,7 @@ choose_best_brush (ppm_t *p, ppm_t *a, int tx, int ty,
         {
           best = i;
           bestdev = dev;
-          brlist = g_list_append (brlist, (void *)i);
+          brlist = g_list_append (brlist, GINT_TO_POINTER (i));
         }
       if (dev < runningvals.devthresh)
         break;
@@ -218,7 +218,7 @@ choose_best_brush (ppm_t *p, ppm_t *a, int tx, int ty,
     }
 
   i = g_rand_int_range (random_generator, 0, g_list_length (brlist));
-  best = (long)((g_list_nth (brlist,i))->data);
+  best = GPOINTER_TO_INT ((g_list_nth (brlist,i))->data);
   g_list_free (brlist);
 
   return best;