atm: dereference of he_dev->rbps_virt in he_init_group()

The prefix decrement causes a very long loop if pci_pool_alloc() failed
in the first iteration. Also I swapped rbps and rbpl arguments.

Reported-by: Juha Leppanen <juha_motorsportcom@luukku.com>
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>