Megan,
I have good luck updating the of libusb in the past without issues. Give it a spin and let us know your outcome.
In the LTIB build environment you can update the libusb spec file dist/lfs-5.1/libusb/libusb.spec to point to the new revisions and add the new version to the LTIB-package-pool directory.
Here are a couple good webpages for libusb.
https://github.com/libusb/libusb/wiki
http://libusb.info/ Regards,
Brad