The virtlogd config is set to rollover logs every 2 MB.

Normally a logrotate config file is also installed to handle cases where
virtlogd is disabled. This is set to rollover weekly with no size
constraint.

As a result logrotate can interfere with virtlogd's, rolling over files
that virtlogd has already taken care of.

This changes logrotate configs to rollover based on a max size
constraint of 2 MB + 1 byte. When virtlogd is running the log files will
never get this large, making logrotate a no-op.

If the user changes the size in virtlogd's config to something larger,
they are responsible for also changing the logrotate config suitably.

The LXC/libxl drivers don't use virtlogd, but there logrotate config is
altered to match the QEMU driver config, for the sake of consistency.
Reviewed-by: NJim Fehlig <jfehlig@suse.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>