Remove warning -Wunused-but-set-variable

[rbuj]

No description provided.

[raveit65]

It seems you fixed those warnings.

gpm-statistics.c: In function 'main':

gpm-statistics.c:1205:8: warning: variable 'retval' set but not used [-Wunused-but-set-variable]

 1205 |  guint retval;

gsd-media-keys-window.c: In function 'msd_media_keys_window_init':

gsd-media-keys-window.c:651:20: warning: variable 'screen' set but not used [-Wunused-but-set-variable]

  651 |         GdkScreen *screen;

Ok one in gpm-manager.c: is left.

[rbuj]

I didn't fix it because it's related to migrating from dbus to gdbus.

        DBusGConnection *connection; /* dbus */
        GDBusConnection *g_connection; /* gdbus */
...
        connection = dbus_g_bus_get (DBUS_BUS_SESSION, &error); /* #include <dbus/dbus-glib.h> */
        g_connection = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, &error); /* #include <gio/gio.h> */

[raveit65]

LGTM,
builds and runs fine.