[gnome-desktop] Silence warnings for increased pointer alignment

[Ernestas Kulik <ernestask src gnome org>]

commit 5db5f5dd7c6ea7a2e2dbf296fcee20617ee566df
Author: Ernestas Kulik <ernestask gnome org>
Date:   Mon Feb 12 18:47:19 2018 +0200

    Silence warnings for increased pointer alignment
    
    Not much to do other than some clever casting, since Xlib insists on
    receiving char pointers.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=793195

 libgnome-desktop/gnome-bg.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/libgnome-desktop/gnome-bg.c b/libgnome-desktop/gnome-bg.c
index eb0dc00..be006a6 100644
--- a/libgnome-desktop/gnome-bg.c
+++ b/libgnome-desktop/gnome-bg.c
@@ -1332,7 +1332,7 @@ gnome_bg_get_surface_from_root (GdkScreen *screen)
        gint format;
        gulong nitems;
        gulong bytes_after;
-       guchar *data;
+       gpointer data;
        Atom type;
        Display *display;
        int screen_num;
@@ -1349,7 +1349,7 @@ gnome_bg_get_surface_from_root (GdkScreen *screen)
                                     gdk_x11_get_xatom_by_name ("_XROOTPMAP_ID"),
                                     0L, 1L, False, XA_PIXMAP,
                                     &type, &format, &nitems, &bytes_after,
-                                    &data);
+                                    (guchar **) &data);
        surface = NULL;
        source_pixmap = NULL;
 
@@ -1422,7 +1422,7 @@ gnome_bg_set_root_pixmap_id (GdkScreen       *screen,
        gint     format;
        gulong   nitems;
        gulong   bytes_after;
-       guchar  *data_esetroot;
+       gpointer data_esetroot;
        Pixmap   pixmap_id;
        Atom     type;
        Display *display;
@@ -1440,7 +1440,7 @@ gnome_bg_set_root_pixmap_id (GdkScreen       *screen,
                                     0L, 1L, False, XA_PIXMAP,
                                     &type, &format, &nitems,
                                     &bytes_after,
-                                    &data_esetroot);
+                                    (guchar **) &data_esetroot);
 
        if (data_esetroot != NULL) {
                if (result == Success && type == XA_PIXMAP &&