fix unloading problems (bug #4019)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/v1-0@5477 65c4cc65-6c06-0410-ace0-fbb531ad65f3

CHANGES

@@ -20,6 +20,8 @@
  -- chan_agent
     -- We now will not pass audio until the agent has acked the call if the configuration
        is set up for the agent to do so.
+ -- chan_alsa
+    -- Fixed problems with the unloading of this module
  -- res_agi
     -- A fix has been added to prevent calls from being hung up when more than one
        call is executing an AGI script calling the GET DATA command.

channels/chan_alsa.c

@@ -1053,10 +1053,12 @@ int load_module()
 int unload_module()
 {
 	int x;
+	
+	ast_channel_unregister(type);
 	for (x=0;x<sizeof(myclis)/sizeof(struct ast_cli_entry); x++)
 		ast_cli_unregister(myclis + x);
-	close(readdev);
-	close(writedev);
+	snd_pcm_close(alsa.icard);
+	snd_pcm_close(alsa.ocard);
 	if (sndcmd[0] > 0) {
 		close(sndcmd[0]);
 		close(sndcmd[1]);