Reduce timeout for reading the USB HUB port status to 1000ms and try to filter
out dead USB HUB devices by implementing an error counter, so that the USB
enumeration thread does not spend all its time reading from non-responding
devices, blocking user-space access in the end.

Tested by: Matthias Apitz <guru@unixarea.de>
MFC after: 1 week
Sponsored by: Mellanox Technologies