NINJA_LOG option uses usesninjalogasweightlist

As-is: Even with NINJA_LOG option, ninja weight list is copied from
ninja log
To-be: uses usesninjalogasweightlist to uses ninja log file directly

If weight list is large(more than 100,000 lines), reading the whole list
spends a few seconds(1-3s). It is ignorable in full build, but it might
be considerable in small build or m nothing scenario.

If weight list comes from ninja log, we can just directly read ninja log
data instead of writing weight list from ninja log outside, and read the
weight list. It doesn't spend additional time because ninja log is
loaded by default.

Bug: 271527305
Test: build with NINJA_LOG
Change-Id: Id7a4cca95898ce439d0a682f9bfd954b462f1849