Fix broken CI build bot

[sffc]

Context: google/myanmar-tools#45

@inferno-chromium said:

getcwd not exist might indicate
build.sh should be WORKDIR $SRC/myanmar-tools instead of
WORKDIR $SRC/myanmar-tools/clients/cpp
this needs a change to OSS-Fuzz repo and then can try here again.
@jonathanmetzman would know and can check in a day or two.

I merged the PR ignoring the failing CI, and am filing this issue to follow up, because the CI continues to fail on other PRs in our repo.

[inferno-chromium]

@sffc - can you please try again. try a new PR in your repo and see if is fixed.

[sffc]

Yep, looks like it's working now: google/myanmar-tools#47

Thanks!