Unneeded libusb linking within libhal

[Danny Kukawka]

On Freitag, 22. Februar 2008, Marcel Holtmann wrote:
> Hi David,
>
> I did some dependency review and I realized that when libusb is found,
> we link libhal against libusb. This is totally unneeded and drags in
> additional dependencies for applications using libhal.
>
> The reason for it is a broken AC_CHECK_LIB usage. The attached patch
> fixes it.

Commited,

Danny