[IrDA]: Fix RCU lock pairing on error path

irlan_client_discovery_indication calls rcu_read_lock and rcu_read_unlock, but
returns without unlocking in an error case.  Fix that by replacing the return
with a goto so that the rcu_read_unlock always gets executed.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Samuel Ortiz samuel@sortiz.org <>
Signed-off-by: David S. Miller <davem@davemloft.net>