bnxt_en: Fix active FEC reporting to ethtool

bnxt_en: Fix active FEC reporting to ethtool

BugLink: https://bugs.launchpad.net/bugs/1963891
commit 84d3c83e6ea7d46cf3de3a54578af73eb24a64f2 upstream.

ethtool --show-fec <interface> does not show anything when the Active
FEC setting in the chip is set to None.  Fix it to properly return
ETHTOOL_FEC_OFF in that case.

Fixes: 8b2775890ad8 ("bnxt_en: Report FEC settings to ethtool.")
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>