net/iucv: Use explicit clean up labels in iucv_init()

Ursula suggested to use explicit labels for clean up in the error path
instead of one `out_free' label, which handles multiple exits, introduced
in commit 38b48292

 ("net/iucv: Convert to hotplug state machine").

Suggested-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-s390@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: rt@linutronix.de
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20161124161013.dukr42y2nwscosk6@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>