ionic: keep ionic dev on lif init fail

If the basic ionic interface works but the lif creation fails,
don't fail the probe.  This will allow us to use the driver to
help inspect the hw/fw/pci interface for debugging purposes.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>