subsystem: tracing: test: fix k_pipe_put_* functions

    k_pipe_put_* functions should take const void* data
    instead of void* data. This can lead to warnings at the
    the -Werror=discarded-qualifiers compiler flag, because the
    the input will be const void* and the parameter will be void*.
    Fix it by replacing void* data with “const void* data”.

Signed-off-by: Bruce Rosier <brucerosier9@gmail.com>