Fix util test dependencies

Fix util test dependencies

The test programs in tests/util did not depend on libutil.a or
libtap.a. So, if libutil.a changed, they were not relinked. Add the
dependencies so correcting a part of libutil will cause the tests to
actually reflect the change.

Change-Id: Iad9d15ef6affd8178d7ef7cb919f66dcce8c61da
Reviewed-on: http://gerrit.openafs.org/2484
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>