usb_disconnect() no longer acquires usb_bus_list_lock, so update its
comment to that effect.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>