CRAS: plc_test - fix make error on make check

While building unittest by "make check", cras_plc_test shows one make
error of variable may be un-initialized. This CL provides the fix.

BUG=none
TEST=(outside chroot) make check -j8

Change-Id: Iacc4b51b299009173b7dff5835eb4af9b7e158ab
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/adhd/+/2561969
Reviewed-by: En-Shuo Hsu <enshuo@chromium.org>
Reviewed-by: Pin-chih Lin <johnylin@chromium.org>
Tested-by: Pin-chih Lin <johnylin@chromium.org>
Auto-Submit: Pin-chih Lin <johnylin@chromium.org>
Commit-Queue: Pin-chih Lin <johnylin@chromium.org>
1 file changed