mono: Specify the expected format rather than failing

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>
(cherry picked from commit c7e24bbe924e18fbde1a9c7a6177410ad0816945)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/audio_filter/channel_mixer/mono.c

@@ -347,13 +347,8 @@ static int OpenFilter( vlc_object_t *p_this )
         return VLC_EGENERIC;
     }
 
-    if( (p_filter->fmt_in.audio.i_format != p_filter->fmt_out.audio.i_format) ||
-        (p_filter->fmt_in.audio.i_format != VLC_CODEC_S16N) ||
-        (p_filter->fmt_out.audio.i_format != VLC_CODEC_S16N) )
-    {
-        /*msg_Err( p_this, "couldn't load mono filter" );*/
-        return VLC_EGENERIC;
-    }
+    p_filter->fmt_in.audio.i_format = VLC_CODEC_S16N;
+    p_filter->fmt_out.audio.i_format = VLC_CODEC_S16N;
 
     /* Allocate the memory needed to store the module's structure */
     p_sys = p_filter->p_sys = malloc( sizeof(filter_sys_t) );