htb: add HTB_DIRECT_QLEN attribute

HTB uses an internal pfifo queue, which limit is not reported
to userland tools (tc), and value inherited from device tx_queue_len
at setup time.

Introduce TCA_HTB_DIRECT_QLEN attribute to allow finer control.

Remove two obsolete pr_err() calls as well.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/pkt_sched.h

@@ -348,6 +348,7 @@ enum {
 	TCA_HTB_INIT,
 	TCA_HTB_CTAB,
 	TCA_HTB_RTAB,
+	TCA_HTB_DIRECT_QLEN,
 	__TCA_HTB_MAX,
 };