selftests: timers: clocksource-switch: Adapt progress to kselftest framework

selftests: timers: clocksource-switch: Adapt progress to kselftest framework

When adapting the test to the kselftest framework, a few printf() calls
indicating test progress were not updated.

Fix this by replacing these printf() calls by ksft_print_msg() calls.

Link: https://lore.kernel.org/r/7dd4b9ab6e43268846e250878ebf25ae6d3d01ce.1733994134.git.geert+renesas@glider.be
Fixes: ce7d101750ff ("selftests: timers: clocksource-switch: adapt to kselftest framework")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>