bnx2x: Remove hw_reset_t function casts

All .rw_reset callbacks except bnx2x_84833_hw_reset_phy() use a
void return type. No callers of .hw_reset check a return value and
bnx2x_84833_hw_reset_phy() unconditionally returns 0. Remove all
hw_reset_t casts and fix the return type to void.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>