paf: convert to new channel layout API

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>

libavformat/paf.c

@@ -127,8 +127,7 @@ static int read_header(AVFormatContext *s)
     ast->codecpar->codec_type     = AVMEDIA_TYPE_AUDIO;
     ast->codecpar->codec_tag      = 0;
     ast->codecpar->codec_id       = AV_CODEC_ID_PAF_AUDIO;
-    ast->codecpar->channels       = 2;
-    ast->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
+    ast->codecpar->ch_layout      = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
     ast->codecpar->sample_rate    = 22050;
     avpriv_set_pts_info(ast, 64, 1, 22050);