binarytree: Add missing parameter to _pkg_str invocation.

When CL:1377100 was rebased onto portage 2.3.49 an extra function call
argument db needed to be added to resolve AttributeErrors.

When rebasing this onto later portage versions, it should be flattened
into CL:1377100.

BUG=chromium:921295
TEST=cros tryjob -g '1454977 1456776' daisy-paladin-tryjob

Change-Id: I9e7a1b7ba0f1e9cd2321dd63f0c55edcf6829f60
Reviewed-on: https://chromium-review.googlesource.com/1456776
Commit-Ready: Allen Webb <allenwebb@google.com>
Tested-by: Allen Webb <allenwebb@google.com>
Reviewed-by: Mathew King <mathewk@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed