Remove unnecessary prune iterations from binary search tool

Previously the binary search tool would do multiple prune iterations to
check if it was complete (using num_bad_items_history). This could lead
to dozens of unneccesary prune iterations. Now we just do one extra prune
iteration before completing by checking the found_items set.

TEST=Run unit tests and test cros_pkg bisector

Change-Id: Id5d6e45c15dcf4b4c0a1c1e6c3feb97d5c0d6d62
Reviewed-on: https://chrome-internal-review.googlesource.com/265275
Commit-Ready: Cassidy Burden <cburden@google.com>
Tested-by: Cassidy Burden <cburden@google.com>
Reviewed-by: Caroline Tice <cmtice@google.com>
1 file changed