Fix a panic that would occur in the VF if the PF driver failed or was
removed from the host kernel. In this case, the VF driver calls
i40evf_close(), but this function does nothing because the driver is in
the resetting state. Because of this, the driver doesn't free its irqs
and causes a kernel panic when it tries to disable MSI-X.

Change-ID: If95644a89e554b4d7be0dca1b6add26f63047129
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>