bnxt_en: Fix VF anti-spoof filter setup.

Fix the logic that sets the enable/disable flag for the source MAC
filter according to firmware spec 1.7.1.

In the original firmware spec. before 1.7.1, the VF spoof check flags
were not latched after making the HWRM_FUNC_CFG call, so there was a
need to keep the func_flags so that subsequent calls would perserve
the VF spoof check setting.  A change was made in the 1.7.1 spec
so that the flags became latched.  So we now set or clear the anti-
spoof setting directly without retrieving the old settings in the
stored vf->func_flags which are no longer valid.  We also remove the
unneeded vf->func_flags.

Fixes: 8eb992e8 ("bnxt_en: Update firmware interface spec to 1.7.6.2.")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>