Tell the device state core a change happened when a channel is freed but not a specific state.

We need to do this because while we know that the freeing of the channel may cause something to become
not in use we do not know this for sure. There may be another channel that is still up which would cause
it to be in use.
(closes issue #13238)
Reported by: kowalma
Patches:
      20090121__bug13238.diff.txt uploaded by Corydon76 (license 14)
Tested by: alecdavis


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@174844 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/channel.c

@@ -1410,7 +1410,10 @@ void ast_channel_free(struct ast_channel *chan)
 	ast_free(chan);
 	AST_RWLIST_UNLOCK(&channels);
 
-	ast_devstate_changed_literal(AST_DEVICE_NOT_INUSE, name);
+	/* Queue an unknown state, because, while we know that this particular
+	 * instance is dead, we don't know the state of all other possible
+	 * instances. */
+	ast_devstate_changed_literal(AST_DEVICE_UNKNOWN, name);
 }
 
 struct ast_datastore *ast_channel_datastore_alloc(const struct ast_datastore_info *info, const char *uid)