i40evf: remove debugging message

If the PF driver fails or is removed from the host, the VF driver will
fill up its log with this message.

Change-ID: I67045f987f7c0d444d21ded403adc509343cdb8f
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>