scripts/perftune.py: fix the zero-IRQ-mask check on big machines
scripts/perftune.py: fix the zero-IRQ-mask check on big machines

The check introduced in "scripts: perftune.py: don't allow cpu-mask that does't include any IRQ CPU"
is broken on big machines.

This patch fixes that.

Fixes scylladb/scylla#3339

Signed-off-by: Vlad Zolotarov <976c0f8d0852ed6439ad273880b400a75a7c41d0@scylladb.com>

syuu1228/seastar,scylladb/seastar,syuu1228/seastar,avikivity/seastar,cloudius-systems/seastar,cloudius-systems/seastar,cloudius-systems/seastar,avikivity/seastar,avikivity/seastar,syuu1228/seastar,dreamsxin/seastar,dreamsxin/seastar,dreamsxin/seastar,scylladb/seastar,scylladb/seastar