[mutter] input-settings: Silence a glib critical

[Rui Matos <rtcm src gnome org>]

commit cfb7297cf1d4c09e45572b3491b332fb52c48331
Author: Rui Matos <tiagomatos gmail com>
Date:   Tue Apr 14 18:27:52 2015 +0200

    input-settings: Silence a glib critical
    
    The scroll-wheel-emulation-button key is 'i' in the schema but it also
    specifies a minimum range of 0 so using get_int() and casting is safe.

 src/backends/meta-input-settings.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/src/backends/meta-input-settings.c b/src/backends/meta-input-settings.c
index d627e71..004044e 100644
--- a/src/backends/meta-input-settings.c
+++ b/src/backends/meta-input-settings.c
@@ -488,7 +488,9 @@ update_trackball_scroll_button (MetaInputSettings  *input_settings,
 
   priv = meta_input_settings_get_instance_private (input_settings);
   input_settings_class = META_INPUT_SETTINGS_GET_CLASS (input_settings);
-  button = g_settings_get_uint (priv->trackball_settings, "scroll-wheel-emulation-button");
+  /* This key is 'i' in the schema but it also specifies a minimum
+   * range of 0 so the cast here is safe. */
+  button = (guint) g_settings_get_int (priv->trackball_settings, "scroll-wheel-emulation-button");
 
   if (device && device_is_trackball (device))
     {