ionic: move lif mutex setup and delete

Move creation and deletion of lif mutex a level out to
lif creation and delete, rather than in init and deinit.
This assures that nothing will get hung if anything is waiting
on the mutex while the driver is clearing the lif while handling
the fw_down/fw_up cycle.

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