net: wan/lmc: dont print format string when not available

dev->name is determined only after calling register_hdlc_device(),
however ,it is used by printk before the name is fully determined.

  [    4.565137] hdlc%d: detected at e8000000, irq 11

Instead of printing out a %d, print hdlc directly

Signed-off-by: Tong Zhang <ztong0001@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>