handover_test.c: properly release lchans in set-ts-use

An upcoming test that uses set-ts-use to release used lchans uncovered
an incomplete release, keeping the lchans occupied due to a missing
release ack. Always ack the release.

Change-Id: Ia22906bfbfcc48b7bd08473a2b17f6b0554687d3
1 file changed