Fix for use-after-free in if_ure(4) driver.

When detaching the if_ure(4) driver, the TX active USB transfer array may
point to freed USB transfers. Given that the number of USB transfers is
very low, simply start all transfers every time there is a packet to
keep safe from use-after-free.

PR: 252608
MFC after: 1 week
Sponsored by: Mellanox Technologies // NVIDIA Networking