red: make burst optional

Documentation advises to set burst to (min+min+max)/(3*avpkt)

Let tc do this automatically if user doesnt provide burst himself.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
diff --git a/tc/q_choke.c b/tc/q_choke.c
index 04a864f..7816f62 100644
--- a/tc/q_choke.c
+++ b/tc/q_choke.c
@@ -133,7 +133,7 @@
 		return -1;
 	}
 	if (wlog >= 10)
-		fprintf(stderr, "CHOKE: WARNING. Burst %d seems to be to large.\n", burst);
+		fprintf(stderr, "CHOKE: WARNING. Burst %d seems to be too large.\n", burst);
 	opt.Wlog = wlog;
 
 	wlog = tc_red_eval_P(opt.qth_min*avpkt, opt.qth_max*avpkt, probability);