[gnome-shell] build: Fix build with clang -Werror

[Ting-Wei Lan <lantw src gnome org>]

commit 1de288c5bb2d8565cc38c18ad88a200b7cfba9d8
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Sat Sep 26 18:32:37 2015 +0800

    build: Fix build with clang -Werror
    
    https://bugzilla.gnome.org/show_bug.cgi?id=755659

 src/gtkactionmuxer.c  |    2 +-
 src/shell-glsl-quad.c |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/src/gtkactionmuxer.c b/src/gtkactionmuxer.c
index 9329a94..1cdf294 100644
--- a/src/gtkactionmuxer.c
+++ b/src/gtkactionmuxer.c
@@ -139,7 +139,7 @@ gtk_action_muxer_list_actions (GActionGroup *action_group)
                             actions);
     }
 
-  return (gchar **) g_array_free (actions, FALSE);
+  return (gchar **)(void *) g_array_free (actions, FALSE);
 }
 
 static Group *
diff --git a/src/shell-glsl-quad.c b/src/shell-glsl-quad.c
index b6c591a..ba62a98 100644
--- a/src/shell-glsl-quad.c
+++ b/src/shell-glsl-quad.c
@@ -84,12 +84,12 @@ shell_glsl_quad_add_glsl_snippet (ShellGLSLQuad    *quad,
 
   if (is_replace)
     {
-      snippet = cogl_snippet_new (hook, declarations, NULL);
+      snippet = cogl_snippet_new ((CoglSnippetHook)hook, declarations, NULL);
       cogl_snippet_set_replace (snippet, code);
     }
   else
     {
-      snippet = cogl_snippet_new (hook, declarations, code);
+      snippet = cogl_snippet_new ((CoglSnippetHook)hook, declarations, code);
     }
 
   if (hook == SHELL_SNIPPET_HOOK_VERTEX ||