qapi/audio: Fix description markup of AudiodevDBusOptions @nsamples

qapi/audio: Fix description markup of AudiodevDBusOptions @nsamples

The description of Member @nsamples is indented incorrectly.  Comes
out like

    Members:
            [...]
	    nsamples (int, optional) – set the number of samples per
	    read/write calls (default to 480,

    10ms at 48kHz).

Fixing the indentation makes it come out like

    Members:
            [...]
	    nsamples (int, optional) – set the number of samples per
	    read/write calls (default to 480, 10ms at 48kHz).

Fixes: 19c628f2f579 (dbus: add -audio dbus nsamples option)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20251103082354.3273027-2-armbru@redhat.com>