In hdlcdrv_register, failure to register the driver causes a crash.
The three callers of hdlcdrv_register all pass valid pointers and
do not fail. The patch eliminates the unnecessary BUG_ON assertion.
Signed-off-by: Aditya Pakki <pakki001@umn.edu> Signed-off-by: David S. Miller <davem@davemloft.net>