iff: make .long_name more descriptive

Signed-off-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/iff.c

@@ -282,7 +282,7 @@ static int iff_read_packet(AVFormatContext *s,
 
 AVInputFormat ff_iff_demuxer = {
     .name           = "IFF",
-    .long_name      = NULL_IF_CONFIG_SMALL("IFF format"),
+    .long_name      = NULL_IF_CONFIG_SMALL("Interchange File Format"),
     .priv_data_size = sizeof(IffDemuxContext),
     .read_probe     = iff_probe,
     .read_header    = iff_read_header,