In the reboot_event handler, unregister the ib devices and enable
the IB layer to release the devices before the reboot.
Fixes: a33a803cfe64 ("net/smc: guarantee removal of link groups in reboot") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>