avformat/hls: release mem resource to fix memleak

fix CID: 1426991
Signed-off-by: Steven Liu <lq@chinaffmpeg.org>
Signed-off-by: Aman Gupta <aman@tmm1.net>
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

libavformat/hls.c

@@ -1473,8 +1473,11 @@ reload:
 
     if (c->http_multiple == -1) {
         uint8_t *http_version_opt = NULL;
-        av_opt_get(v->input, "http_version", AV_OPT_SEARCH_CHILDREN, &http_version_opt);
-        c->http_multiple = http_version_opt && strncmp((const char *)http_version_opt, "1.1", 3) == 0;
+        int r = av_opt_get(v->input, "http_version", AV_OPT_SEARCH_CHILDREN, &http_version_opt);
+        if (r >= 0) {
+            c->http_multiple = strncmp((const char *)http_version_opt, "1.1", 3) == 0;
+            av_freep(&http_version_opt);
+        }
     }
 
     seg = next_segment(v);