tools/rtla: Replace timerlat_top_usage("...") with fatal("...")

tools/rtla: Replace timerlat_top_usage("...") with fatal("...")

A long time ago, when the usage help was short, it was a favor
to the user to show it on error. Now that the usage help has
become very long, it is too noisy to dump the complete help text
for each typo after the error message itself.

Replace timerlat_top_usage("...\n") with fatal("...") on errors.

Remove the already unused 'usage' argument from timerlat_top_usage().

Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Reviewed-by: Tomas Glozar <tglozar@redhat.com>
Link: https://lore.kernel.org/r/20251011082738.173670-3-costa.shul@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>