bnxt_en: Fix VF mac address regression.

The recent commit to always forward the VF MAC address to the PF for
approval may not work if the PF driver or the firmware is older.  This
will cause the VF driver to fail during probe:

  bnxt_en 0000:00:03.0 (unnamed net_device) (uninitialized): hwrm req_type 0xf seq id 0x5 error 0xffff
  bnxt_en 0000:00:03.0 (unnamed net_device) (uninitialized): VF MAC address 00:00:17:02:05:d0 not approved by the PF
  bnxt_en 0000:00:03.0: Unable to initialize mac address.
  bnxt_en: probe of 0000:00:03.0 failed with error -99

We fix it by treating the error as fatal only if the VF MAC address is
locally generated by the VF.

Fixes: 707e7e96 ("bnxt_en: Always forward VF MAC address to the PF.")
Reported-by: Seth Forshee <seth.forshee@canonical.com>
Reported-by: Siwei Liu <loseweigh@gmail.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>