mod_fifo: Avoid getting a var when we won't use it

src/mod/applications/mod_fifo/mod_fifo.c

@@ -468,9 +468,8 @@ static switch_status_t on_dtmf(switch_core_session_t *session, void *input, swit
 			switch_channel_t *bchan = switch_core_session_get_channel(bleg);
 			switch_channel_t *channel = switch_core_session_get_channel(session);
 
-			const char *consumer_exit_key = switch_channel_get_variable(channel, "fifo_consumer_exit_key");
-
 			if (switch_channel_test_flag(switch_core_session_get_channel(session), CF_BRIDGE_ORIGINATOR)) {
+				const char *consumer_exit_key = switch_channel_get_variable(channel, "fifo_consumer_exit_key");
 				if (consumer_exit_key && dtmf->digit == *consumer_exit_key) {
 					switch_channel_hangup(bchan, SWITCH_CAUSE_NORMAL_CLEARING);
 					return SWITCH_STATUS_BREAK;