i40evf: refactor reset

A recent change to the shutdown flow messed up the reset flow. Since
i40evf_down now holds the critical section lock, we cannot call it from
the reset handler, which also holds the lock. To do so causes a deadlock
accompanied by wailing and gnashing of teeth. This is easily triggered
by running an ethtool self-test on the PF device.

Instead, we move the relevant portions of i40evf_down into the reset
handler and bend them to our will. Additionally, we can optimize the
reinit path by not deleting the MAC and VLAN filters and then adding
them back again. Instead, we just set the 'add' flag and let the
watchdog resynchronize the filter list with the PF driver. We also
reword a few messages to make them more consistent with the rest of the
driver.

Change-ID: I03dd92ae736f7719fca3564b12a2cf9b98c6cb18
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Jim Young <james.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>