bnxt_en: Report Active FEC encoding during link up.

The current code is reporting the FEC configured settings during link up.
Change it to report the more useful active FEC encoding that may be
negotiated or auto detected.

Reviewed-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>