tools/rtla: drop __NR_sched_getattr

It's not used since commit 084ce16d ("tools/rtla:
Remove unused sched_getattr() function").

Link: https://lore.kernel.org/c355dc9ad23470098d6a8d0f31fbd702551c9ea8.1728552769.git.jstancek@redhat.com


Signed-off-by: Jan Stancek <jstancek@redhat.com>
Reviewed-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>