CRAS: test_client - Switch to localtime_r

localtime returns a pointer to a global, which can break. Static
analysis will complain about any use of this as it's so easy to get
wrong.

Change-Id: Ia0e80da80f26004bc4604d907e32c51a91d43454
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/adhd/+/2554517
Reviewed-by: Hsinyu Chao <hychao@chromium.org>
Tested-by: Dylan Reid <dgreid@chromium.org>
Commit-Queue: Dylan Reid <dgreid@chromium.org>
1 file changed