MT#61856 recording: destroy mutex when closing file

When closing output file, unlinking paths,
also destroy the according mutex.

Change-Id: Ic8abab4d52e4bfc65eba4786f41dac124921c888

daemon/recording.c

@@ -686,6 +686,8 @@ static void rec_pcap_meta_discard_file(call_t *call) {
 
 	unlink(recording->pcap.recording_path);
 	unlink(recording->pcap.meta_filepath);
+
+	mutex_destroy(&recording->pcap.recording_lock);
 	g_clear_pointer(&recording->pcap.meta_filepath, free);
 }