ice: Fix double VLAN error when entering promisc mode

ice: Fix double VLAN error when entering promisc mode

Avoid enabling or disabling VLAN 0 when trying to set promiscuous
VLAN mode if double VLAN mode is enabled. This fix is needed
because the driver tries to add the VLAN 0 filter twice (once for
inner and once for outer) when double VLAN mode is enabled. The
filter program is rejected by the firmware when double VLAN is
enabled, because the promiscuous filter only needs to be set once.

This issue was missed in the initial implementation of double VLAN
mode.

Fixes: 5eda8afd6bcc ("ice: Add support for PF/VF promiscuous mode")
Signed-off-by: Grzegorz Siwik <grzegorz.siwik@intel.com>
Link: https://lore.kernel.org/all/CAK8fFZ7m-KR57M_rYX6xZN39K89O=LGooYkKsu6HKt0Bs+x6xQ@mail.gmail.com/
Tested-by: Jaroslav Pulchart <jaroslav.pulchart@gooddata.com>
Tested-by: Igor Raits <igor@gooddata.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>