bisect-kit: Fix the error condition for the directory existence check.

BUG=b:329263312
TEST=./run_tests.sh

Change-Id: I81a246b50207019137c44ed1bbcf97f97524d471
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/bisect-kit/+/5367361
Reviewed-by: Cheng-Yu Lee <cylee@google.com>
Commit-Queue: MD Nayeem Jahan Rafi <njrafi@chromium.org>
Tested-by: MD Nayeem Jahan Rafi <njrafi@chromium.org>
1 file changed