i40evf: Fix a hardware reset support in VF driver

This patch fixes a hardware reset support in VF driver.
It is needed because when a hardware reset is detected
adapter->state is in __I40EVF_RESETTING state before
i40evf_reset_task is called. Without this patch
unloading VF driver after a hardware reset ends
with a system crash.

Signed-off-by: Paweł Jabłoński <pawel.jablonski@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>