crosperf: fix a bug where we tar the world in results_cache

This consumes potentially tons of disk. Also we'll raise in this
situation from now on, since it never seems to be what we want.

BUG=chromium:1079048
TEST=Unittests

Change-Id: Ie1933b5ff0b939777d7e1d6d35dd5a29039ca07a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2220291
Reviewed-by: Zhizhou Yang <zhizhouy@google.com>
Tested-by: George Burgess <gbiv@chromium.org>
1 file changed