Revert "iavf: Do not restart Tx queues after reset task failure"

This reverts commit 08f1c147.

Netdev is no longer being detached during reset, so this fix can be
reverted. We leave the removal of "hacky" IFF_UP flag update.

Signed-off-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>