i40e: clear mac filter count on reset

When a VF is reset, it gets a new VSI, so all of its MAC filters go
away. Correctly set the number of filters to 0 when freeing VF
resources. This corrects a problem with failure to add filters when the
VF driver is reloaded.

Change-ID: I2acbecf734287b67473bb225293e14b5096acbef
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c

@@ -811,6 +811,7 @@ static void i40e_free_vf_res(struct i40e_vf *vf)
 		i40e_vsi_release(pf->vsi[vf->lan_vsi_idx]);
 		vf->lan_vsi_idx = 0;
 		vf->lan_vsi_id = 0;
+		vf->num_mac = 0;
 	}
 	msix_vf = pf->hw.func_caps.num_msix_vectors_vf;