selftests/perf_events: Fix spelling mistake "sycnhronize" -> "synchronize"

There is a spelling mistake in an error message. Fix it.

Link: https://lore.kernel.org/r/20240327110649.283925-1-colin.i.king@gmail.com


Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Kyle Huey <khuey@kylehuey.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>