willis: Show progress at 30fps.

Do an unbuffered write. Output was being buffered because it was without newline.

And really only show output at 30fps.

BUG=None
TEST=go run willis.go

Change-Id: I686785f6e0eba13fd92ecf9404cc5a2e727ba58e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2340842
Commit-Queue: Junichi Uekawa <uekawa@chromium.org>
Tested-by: Junichi Uekawa <uekawa@chromium.org>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
1 file changed