kselftest/runner: Print new line in print of timeout log

If a timeout failure occurs, kselftest kills the test process and prints
the timeout log.  If the test process has killed while printing a log
that ends with new line, the timeout log can be printed in middle of the
test process output so that it can be seems like a comment, as below:

    # test_process_log	not ok 3 selftests: timers: nsleep-lat # TIMEOUT

This commit avoids such problem by printing one more line before the
TIMEOUT failure log.

Signed-off-by: SeongJae Park <sjpark@amazon.de>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>