Replace all occurrences of AVERROR_IO with AVERROR(EIO).

Originally committed as revision 9760 to svn://svn.ffmpeg.org/ffmpeg/trunk
diff --git a/libavformat/mpeg.c b/libavformat/mpeg.c
index fd4e5b0..d831b71 100644
--- a/libavformat/mpeg.c
+++ b/libavformat/mpeg.c
@@ -232,7 +232,7 @@
         last_sync = url_ftell(&s->pb);
     //printf("startcode=%x pos=0x%"PRIx64"\n", startcode, url_ftell(&s->pb));
     if (startcode < 0)
-        return AVERROR_IO;
+        return AVERROR(EIO);
     if (startcode == PACK_START_CODE)
         goto redo;
     if (startcode == SYSTEM_HEADER_START_CODE)