add missing using DoAll

Needed by newer gtest 1.10 release.

BUG=None
TEST=build passes w/gtest 1.8 & 1.10

Change-Id: I4d750d3c80da816316ee47267bc4732f5b580496
Reviewed-on: https://chrome-internal-review.googlesource.com/c/chromeos/thermald/+/3620287
Reviewed-by: Allen Webb <[email protected]>
Commit-Queue: Mike Frysinger <[email protected]>
Tested-by: Mike Frysinger <[email protected]>
1 file changed