[clutter-gst/clutter-gst-3.0] video-sink: Fix compilation error

[Bastien Nocera <hadess src gnome org>]

commit 3b3c5d4927968f1bd823c4869425897dd2c57768
Author: Bastien Nocera <hadess hadess net>
Date:   Thu Apr 13 10:40:17 2017 +0200

    video-sink: Fix compilation error
    
    clutter-gst-video-sink.c: In function ‘clutter_gst_video_sink_setup_balance’:
    clutter-gst-video-sink.c:831:44: error: format not a string literal, argument types not checked 
[-Werror=format-nonliteral]
        priv->custom_start + 2);
        ^~~~
    
    https://bugzilla.gnome.org/show_bug.cgi?id=781264

 clutter-gst/clutter-gst-video-sink.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/clutter-gst/clutter-gst-video-sink.c b/clutter-gst/clutter-gst-video-sink.c
index f325a09..2cbabe6 100644
--- a/clutter-gst/clutter-gst-video-sink.c
+++ b/clutter-gst/clutter-gst-video-sink.c
@@ -796,6 +796,9 @@ static const gchar *color_balance_shader =
   "  return clutter_gst_yuv_to_rgb (corrected_yuv);\n"
   "}\n";
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wformat-nonliteral"
+
 static void
 clutter_gst_video_sink_setup_balance (ClutterGstVideoSink *sink,
                                       CoglPipeline *pipeline)
@@ -890,6 +893,8 @@ clutter_gst_video_sink_setup_balance (ClutterGstVideoSink *sink,
     }
 }
 
+#pragma GCC diagnostic pop
+
 /* YUV <-> RGB conversions */
 
 static const gchar *no_color_conversions_shader =