i40e: use QOS field consistently

In i40e_ndo_set_vf_port_vlan, we were using the QOS value
inconsistently, sometimes shifting it, sometimes not. Do the shift-and-
or operation correctly, once, and use the result consistently everywhere
in the function.

Change-ID: I46f062f3edc90a8a017ecec9137f4d1ab0ab9e41
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>