bnxt_en: Cleanup bnxt_hwrm_func_cfg().

1. Use local variable pf for repeated access to this pointer.

2.  The 2nd argument num_vfs was unnecessarily declared as pointer to int.
This function doesn't change num_vfs so change the argument to int.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>