qapi/trace: Tidy up trace-event-get-state, -set-state documentation

trace-event-set-state's explanation of how events are selected is
under "Features".  Doesn't belong there.  Simply delete it, as it
feels redundant with documentation of member @name.

trace-event-get-state's explanation is under "Returns".  Tolerable,
but similarly redundant.  Delete it, too.

Cc: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20230720071610.1096458-5-armbru@redhat.com>
1 file changed