ice: Fix napi delete calls for remove

In the remove path, the vsi->netdev is being set to NULL before the call
to free vectors. This is causing the netif_napi_del call to never be made.

Add a call to ice_napi_del to the same location as the calls to
unregister_netdev and just prior to them. This will use the reverse flow
as the register and netif_napi_add calls.

Signed-off-by: Dave Ertman <david.m.ertman@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>