net: aquantia: Change confusing no_ff_addr to more meaningful name

The address to check if HW is not dead/hang could be stored in
capabilities, since it is a constant. Change its name to better reflect
the idea.

Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>