bnxt_en: Improve bnxt_probe_phy().

If the 2nd parameter fw_dflt is not set, we are calling bnxt_probe_phy()
after the firmware has reset.  There is no need to query the current
PHY settings from firmware as these settings may be different from
the ethtool settings that the driver will re-establish later.  So
return earlier in bnxt_probe_phy() to save one firmware call.

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