It doesn't make much sense to do this, the result is very similar to including
to objects directly in the output binary without going through an intermediate
target.
The linkage of test-libudev was rather strange too: udev_link_with is used to
allow udev to be linked to a static version of libshared, so that udev is not
linked to libshared.so. But here we were using both, defeating the purpose of
udev_link_with. I don't think it matters what the test is linked to, so let's
use the non-static linkage to save space.