daala: enc: remove redundant chroma initialization

The chroma is already setup later in the `Open` function.

modules/codec/daala.c

@@ -602,7 +602,6 @@ static int OpenEncoder( vlc_object_t *p_this )
         return VLC_ENOMEM;
     p_enc->p_sys = p_sys;
 
-    p_enc->fmt_in.i_codec = VLC_CODEC_I420;
     p_enc->fmt_out.i_codec = VLC_CODEC_DAALA;
 
     config_ChainParse( p_enc, ENC_CFG_PREFIX, ppsz_enc_options, p_enc->p_cfg );