perf cs-etm: Fix erroneous comment

perf cs-etm: Fix erroneous comment

The comment just before initialising the decoder is plane wrong since it
is part of the decoding queue setup function and the operation code
specifically mention that trace data is to be decoded rather than printed
out.

This patch simply fix the comment to prevent people from getting really
confused.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki K Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190212171618.25355-8-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>