[tracker] Fix tracker-extract-libav memory leak

[Carlos Garnacho <carlosg src gnome org>]

commit fb896dc2107fdcb610ee0a1c91e1a7b5910f4a60
Author: Andrew Branson <andrew branson jollamobile com>
Date:   Sat Oct 8 23:59:02 2016 +0200

    Fix tracker-extract-libav memory leak
    
    https://bugzilla.gnome.org/show_bug.cgi?id=772611

 src/tracker-extract/tracker-extract-libav.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/tracker-extract/tracker-extract-libav.c b/src/tracker-extract/tracker-extract-libav.c
index cd8147b..b2597f9 100644
--- a/src/tracker-extract/tracker-extract-libav.c
+++ b/src/tracker-extract/tracker-extract-libav.c
@@ -77,7 +77,7 @@ tracker_extract_get_metadata (TrackerExtractInfo *info)
        }
 
        if (!audio_stream && !video_stream) {
-               avformat_free_context (format);
+               avformat_close_input (&format);
                g_free (uri);
                return FALSE;
        }
@@ -278,7 +278,7 @@ tracker_extract_get_metadata (TrackerExtractInfo *info)
 
        g_free (uri);
 
-       avformat_free_context (format);
+       avformat_close_input (&format);
 
        tracker_extract_info_set_resource (info, metadata);
        g_object_unref (metadata);