Fix iterating over long running method buffers when flushing

When iterating over the long running buffers, we used to use unsigned
indices and the way the loop was written it was expecting signed values.
The loop exit check expected -1 but for unsigned this doesn't work.
Fixed the check to not expect -1 and also used signed index.

Drive-by-fix: Use correct type for unique_ptr.

Bug: 352518093
Test: Manual test
Change-Id: I8461919d7c20e3d76fa9e10783f8dd1f7ef950e0

0 files changed, 0 insertions, 0 deletions