opus: remove dead code

opus_prepare_header is "too small to fail"

modules/codec/opus.c

@@ -611,14 +611,8 @@ static int OpenEncoder(vlc_object_t *p_this)
 
     OpusHeader header;
 
-    if (opus_prepare_header(enc->fmt_out.audio.i_channels,
-            enc->fmt_out.audio.i_rate,
-            &header))
-    {
-        msg_Err(enc, "Failed to prepare header.");
-        status = VLC_ENOMEM;
-        goto error;
-    }
+    opus_prepare_header(enc->fmt_out.audio.i_channels,
+            enc->fmt_out.audio.i_rate, &header);
 
     /* needed for max encoded size calculation */
     sys->nb_streams = header.nb_streams;

modules/codec/opus_header.c

@@ -299,7 +299,7 @@ static int comment_pad(char **comments, size_t *length)
     return 0;
 }
 
-int opus_prepare_header(unsigned channels, unsigned rate, OpusHeader *header)
+void opus_prepare_header(unsigned channels, unsigned rate, OpusHeader *header)
 {
     header->version = 1;
     header->channels = channels;
@@ -309,8 +309,6 @@ int opus_prepare_header(unsigned channels, unsigned rate, OpusHeader *header)
     header->gain = 0; // 0dB
     header->channel_mapping = header->channels > 8 ? 255 :
                               header->channels > 2;
-
-    return 0;
 }
 
 static int opus_header_to_packet(const OpusHeader *h, unsigned char *packet, int len)

modules/codec/opus_header.h

@@ -44,7 +44,7 @@ typedef struct {
 } OpusHeader;
 
 int opus_header_parse(const unsigned char *header, int len, OpusHeader *h);
-int opus_prepare_header(unsigned channels, unsigned rate, OpusHeader *header);
+void opus_prepare_header(unsigned channels, unsigned rate, OpusHeader *header);
 int opus_write_header(uint8_t **p_extra, int *i_extra, OpusHeader *header, const char *vendor);
 
 #endif