Remove $FreeBSD$: one-line .c comment pattern

Remove /^/[*/]\s*\$FreeBSD\$.*\n/

Add missing mutex unlock in failure case.

Differential Revision: https://reviews.freebsd.org/D23430
Submitted by: cem
Reported by: Coverity
Coverity CID: 1368773
MFC after: 3 days
Sponsored by: Mellanox Technologies

Only call libusb_hotplug_enumerate() once from libusb_hotplug_register_callback().
Else when registering multiple filters the same USB device may appear twice in
the list.

MFC after: 3 days
Sponsored by: Mellanox Technologies

Fix support for LIBUSB_HOTPLUG_ENUMERATE in libusb. Currently all
devices are enumerated regardless of of the LIBUSB_HOTPLUG_ENUMERATE
flag. Make sure when the flag is not specified no arrival events are
generated for currently enumerated devices.

MFC after: 3 days
Sponsored by: Mellanox Technologies

Implement libusb_hotplug_register_callback() and
libusb_hotplug_deregister_callback() for the LibUSB v1.0 API and
update the libusb(3) manual page.

Approved by: re (kib)
Requested by: swills
MFC after: 1 week