- Remove an incorrect assertion that can trigger when downing an interface.
- Stop the interface during detach to avoid panics when unloading the
driver.
- A few locking fixes to be more consistent with other FreeBSD drivers:
- Protect if_drv_flags with the driver lock, not atomic ops
- Hold the driver lock when adjusting multicast state.
- Hold the driver lock while adjusting if_capenable.
PR: kern/180791 [1,2]
Submitted by: Shakar Klein @ Mellanox [1,2]
MFC after: 3 days