standalone_test: unset log level on root logger when

Other modules may have messed with the root logger already, so if we
don't reset the root logger log level, messages go through the logger
even after we add the console and file handlers later.

This problem wasn't visible before because an autotest module was
unconditionally setting the root logger log level to DEBUG, but a recent
patch I sent to autotest removes that unconditional logging setup code.

This patch also renames configure_logging() to reset_logging(), as it
doesn't configure any handler, but just remove the existing logging
configuration).

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
./run: make stdout redirect/restore API simpler

Today, if _restore_stdout() is called twice, stdout gets silenced again.
Instead of having API that requires the caller to remember what's the
internal state of the object to know what will happen, we can simply
have two separate methods to redirect and restore stdout.

The main problem with the current approach is that it makes it very
difficult to gradually disable the hack in various parts of the code[1],
as changing the moment we silence/restore stdout could break existing
parts of the code that calls the switch() method assuming stdout is
already silenced.

[1] In a perfect world we wouldn't need any stdout hacking at all, we
    would just need to ask the test runner and autotest to be more
    silent. But to achieve that, we need to do it gradually (e.g. trying
    to disable stdout/stderr only when actually running the tests, not
    when parsing configs or loading modules)

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
bootstrap.py: fix log message formatting

The arguments for logging.info are the format string parameters
themselves, not a tuple. This was causing logging error tracebacks on my
tests.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>