net/hns3: cancel heartbeat alarm when VF reset

net/hns3: cancel heartbeat alarm when VF reset

The purpose of the heartbeat alarm is to keep alive for VF. The mailbox
channel is disabled when VF is reset, and the heartbeat mailbox message
will fail to send. If the reset is not complete, the error information
about the heartbeat sending failure will be printed continuously.
In fact, VF does set alive when VF restore its configuration. So the
heartbeat alarm can be canceled to prepare to start reset and start the
alarm when start service.

Signed-off-by: Huisong Li <lihuisong@huawei.com>
Signed-off-by: Dongdong Liu <liudongdong3@huawei.com>