perf: make sure to explicitly disable any profiler after the first iteration
The current code work, because of some edge behavior of the `profile` class. We
make it explicit that the profiler is not in effect more than once.
test: add missing 'cd ..' to test case
Differential Revision: https://phab.mercurial-scm.org/D6439
match: remove an obsolete comment about util.finddirs()
Obsolete since
8e55c0c642c (util: make util.dirs() and util.finddirs()
include root directory (API), 2017-05-16).
Differential Revision: https://phab.mercurial-scm.org/D6433