scripts/perftune.py: change the get_cpu_mask logic for bonding interface
scripts/perftune.py: change the get_cpu_mask logic for bonding interface

Return the narrowest CPU mask among the slave masks instead of the widest.
We don't want to bind any shard on the CPU that may be used for IRQs handling.

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

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