Documentation/rtla: Rename sample/ to example/

The sample/ directory in tools/tracing/rtla was renamed to example/ in
an earlier commit.

Rename it also in the documentation.

Reviewed-by: Wander Lairson Costa <wander@redhat.com>
Link: https://lore.kernel.org/r/20251126144205.331954-7-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>

Author: lenticularis39

Documentation/tools/rtla/common_timerlat_options.txt

@@ -64,4 +64,4 @@
 
         Set timerlat to run without workload, waiting for the user to dispatch a per-cpu
         task that waits for a new period on the tracing/osnoise/per_cpu/cpu$ID/timerlat_fd.
-        See linux/tools/rtla/sample/timerlat_load.py for an example of user-load code.
+        See linux/tools/rtla/example/timerlat_load.py for an example of user-load code.