netxen: deinline and sparse fix

Get rid of dubious casts to (void *) which causes a sparse warning.
And move largeish function from inline to the one file that uses the code,
the compiler can then decide to inline it.

Compile tested only.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>