transcode: set b_master_sync correctly

(cherry picked from commit fd89198cdb7e6121380f374235ffdb7f6314d98e)
Signed-off-by: Ilkka Ollakka <ileoo@videolan.org>

modules/stream_out/transcode/transcode.c

@@ -341,7 +341,7 @@ static int Open( vlc_object_t *p_this )
 
     p_sys->f_scale = var_GetFloat( p_stream, SOUT_CFG_PREFIX "scale" );
 
-    p_sys->b_master_sync = var_InheritURational( p_stream, &p_sys->fps_num, &p_sys->fps_den, SOUT_CFG_PREFIX "fps" );
+    p_sys->b_master_sync = var_InheritURational( p_stream, &p_sys->fps_num, &p_sys->fps_den, SOUT_CFG_PREFIX "fps" ) == VLC_SUCCESS;
 
     p_sys->i_width = var_GetInteger( p_stream, SOUT_CFG_PREFIX "width" );