net/mlx4_en: Avoid scheduling restart task if it is already running

stable inclusion
from linux-4.19.164
commit 7eb728345c422220407b68e339abd4a0cfb26439

--------------------------------

[ Upstream commit fed91613 ]

Add restarting state flag to avoid scheduling another restart task while
such task is already running. Change task name from watchdog_task to
restart_task to better fit the task role.

Fixes: 1e338db5 ("mlx4_en: Fix a race at restart task")
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>

Signed-off-by: Aichun Li <liaichun@huawei.com>
reviewed-by: wangxiaopeng <wangxiaopeng7@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>