avcodec/codec_internal: Add macro to set AVCodec.long_name

It reduces typing: Before this patch, there were 105 codecs
whose long_name-definition exceeded the 80 char line length
limit. Now there are only nine of them.

Signed-off-by: Andreas Rheinhardt <[email protected]>
diff --git a/libavcodec/vmdaudio.c b/libavcodec/vmdaudio.c
index 158b02f..7e4477e 100644
--- a/libavcodec/vmdaudio.c
+++ b/libavcodec/vmdaudio.c
@@ -230,7 +230,7 @@
 
 const FFCodec ff_vmdaudio_decoder = {
     .p.name         = "vmdaudio",
-    .p.long_name    = NULL_IF_CONFIG_SMALL("Sierra VMD audio"),
+    CODEC_LONG_NAME("Sierra VMD audio"),
     .p.type         = AVMEDIA_TYPE_AUDIO,
     .p.id           = AV_CODEC_ID_VMDAUDIO,
     .priv_data_size = sizeof(VmdAudioContext),