cups: fix cups build against libusb/libusb-1.0

cups was getting confused between libusb and libusb-1.0, the dependency
said libusb, but a configure script was seeing libusb-1.0 available and
preferred it, but then failed during link.  Also, an install target had
some line wrapping problems.

Signed-off-by: Russell Senior <russell@personaltelco.net>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/packages@35236 3c298f89-4303-0410-b956-a3cf2f4a3e73