lib: move get_numcpus to librttest.[ch] get_numcpus() can be used by other tests therefore it is better to move it to a shared place. Link: https://lore.kernel.org/ltp/[email protected]/ Reviewed-by: Cyril Hrubis <[email protected]> Reviewed-by: Petr Vorel <[email protected]> Signed-off-by: Attila Fazekas <[email protected]>