avformat/hdsenc: Use av_freep() avoid leaving stale pointers in memory

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 16d763fa)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/hdsenc.c

@@ -145,15 +145,15 @@ static void hds_free(AVFormatContext *s)
         if (os->ctx && os->ctx_inited)
             av_write_trailer(os->ctx);
         if (os->ctx && os->ctx->pb)
-            av_free(os->ctx->pb);
+            av_freep(&os->ctx->pb);
         if (os->ctx)
             avformat_free_context(os->ctx);
-        av_free(os->metadata);
+        av_freep(&os->metadata);
         for (j = 0; j < os->nb_extra_packets; j++)
-            av_free(os->extra_packets[j]);
+            av_freep(&os->extra_packets[j]);
         for (j = 0; j < os->nb_fragments; j++)
-            av_free(os->fragments[j]);
-        av_free(os->fragments);
+            av_freep(&os->fragments[j]);
+        av_freep(&os->fragments);
     }
     av_freep(&c->streams);
 }
@@ -499,7 +499,7 @@ static int hds_flush(AVFormatContext *s, OutputStream *os, int final,
         if (remove > 0) {
             for (i = 0; i < remove; i++) {
                 unlink(os->fragments[i]->file);
-                av_free(os->fragments[i]);
+                av_freep(&os->fragments[i]);
             }
             os->nb_fragments -= remove;
             memmove(os->fragments, os->fragments + remove,