i40e/i40evf: remove useless initializer

This initializer isn't needed because the variable is assigned right
away.

Change-ID: I6ce3edb3f4e0364db248a7a0bcc62ca95c01d941
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>