ensure channel's scheduling context is freed (issue #5788)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.2@7268 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channel.c

@@ -909,6 +909,9 @@ void ast_channel_free(struct ast_channel *chan)
 		free(chan->tech_pvt);
 	}
 
+	if (chan->sched)
+		sched_context_destroy(chan->sched);
+
 	ast_copy_string(name, chan->name, sizeof(name));
 
 	/* Stop monitoring */
@@ -1294,8 +1297,10 @@ int ast_hangup(struct ast_channel *chan)
 		ast_closestream(chan->stream);
 	if (chan->vstream)		/* Close video stream */
 		ast_closestream(chan->vstream);
-	if (chan->sched)
+	if (chan->sched) {
 		sched_context_destroy(chan->sched);
+		chan->sched = NULL;
+	}
 	
 	if (chan->generatordata)	/* Clear any tone stuff remaining */ 
 		chan->generator->release(chan, chan->generatordata);