docs: Remove duplicated words in trace/osnoise-tracer

There are 2 duplicated words found in osnoise tracer documentation.
This patch removes them.

Signed-off-by: Oscar Shiang <oscar0225@livemail.tw>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Link: https://lore.kernel.org/r/TYCP286MB1913117487F390E3BCE38B15A1399@TYCP286MB1913.JPNP286.PROD.OUTLOOK.COM


Signed-off-by: Jonathan Corbet <corbet@lwn.net>