avformat/hdsenc: Simplify code by using avio_closep()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/hdsenc.c

@@ -140,8 +140,7 @@ static void hds_free(AVFormatContext *s)
     for (i = 0; i < s->nb_streams; i++) {
         OutputStream *os = &c->streams[i];
         if (os->out)
-            avio_close(os->out);
-        os->out = NULL;
+            avio_closep(&os->out);
         if (os->ctx && os->ctx_inited)
             av_write_trailer(os->ctx);
         if (os->ctx && os->ctx->pb)
@@ -311,8 +310,7 @@ static void close_file(OutputStream *os)
     avio_seek(os->out, 0, SEEK_SET);
     avio_wb32(os->out, pos);
     avio_flush(os->out);
-    avio_close(os->out);
-    os->out = NULL;
+    avio_closep(&os->out);
 }
 
 static int hds_write_header(AVFormatContext *s)