ibmvnic: restore adapter state on failed reset

In a failed reset, driver could end up in VNIC_PROBED or VNIC_CLOSED
state and cannot recover in subsequent resets, leaving it offline.
This patch restores the adapter state to reset_state, the original
state when reset was called.

Fixes: b27507bb ("net/ibmvnic: unlock rtnl_lock in reset so linkwatch_event can run")
Fixes: 2770a798 ("ibmvnic: Introduce hard reset recovery")
Signed-off-by: Dany Madden <drt@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>