Don't discard root_config information when resolving SetArgs

SetArgs include which ROOT they are destined for, so use that information
when resolving the initial_arg_list rather than assuming the SetArg is
meant for the default ROOT.

This change means lakitu no longer fails with a collision between udev
and systemd when libcap is uprevved.

BUG=chromium:1039933
TEST=`emerge-lakitu -pgDu --with-bdeps=y --rebuild-if-new-rev target-os`

Change-Id: Ifded0753a3a6952f01b39f46b15cc734320b7f70
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/portage_tool/+/2048533
Tested-by: Chris McDonald <cjmcdonald@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Chris McDonald <cjmcdonald@chromium.org>
1 file changed