Narrow down build dependences of duration_test
Narrow down build dependences of duration_test

In 0ea6df, duration_test was made to link against all tests/*.o files.
This isn't necessary, as it only needs tests/exception_utils.o.  This
patch narrows down duration_test's dependences to only
exception_utils.

Signed-off-by: Dejan Mircevski <1e9694aae17a51d4875d9bf4a0d0e20ef37c1b85@scylladb.com>
Message-Id: <20190508211630.108228-1-1e9694aae17a51d4875d9bf4a0d0e20ef37c1b85@scylladb.com>

scylladb/scylla,scylladb/scylla,avikivity/scylla,avikivity/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla