wrong week to quit sniffing glue

git-svn-id: http://svn.openzap.org/svn/openzap/trunk@900 a93c3328-9c30-0410-af19-c9cd2b2d52af

libs/openzap/src/zap_io.c

@@ -1225,7 +1225,7 @@ OZ_DECLARE(zap_status_t) zap_channel_done(zap_channel_t *zchan)
 	zchan->pre_buffer_size = 0;
 	zap_mutex_unlock(zchan->pre_buffer_mutex);
 
-	if (!zchan->dtmf_buffer) {
+	if (zchan->dtmf_buffer) {
 		zap_buffer_zero(zchan->dtmf_buffer);
 	}