Let's skip printing anything if there's nothing to see. This makes it so
the file length is 0 instead of 1, for the newline, and helps scripts
figure out if there's anything to see in these files.

Cc: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20210628030150.2627905-1-swboyd@chromium.orgSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>