avformat/hls: always return EOF for unneeded playlist streams

Even if we returned AVERROR_EOF previously due to playlist no longer
being needed, we may still be called again, and we do not want to
trigger a segment download in that case.
Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>

libavformat/hls.c

@@ -653,6 +653,9 @@ static int read_data(void *opaque, uint8_t *buf, int buf_size)
     HLSContext *c = v->parent->priv_data;
     int ret, i;
 
+    if (!v->needed)
+        return AVERROR_EOF;
+
 restart:
     if (!v->input) {
         /* If this is a live stream and the reload interval has elapsed since