crypto: iaa - Fix nr_cpus < nr_iaa case

In the Linux kernel, the following vulnerability has been resolved: crypto: iaa - Fix nr_cpus < nr_iaa case If nr_cpus < nr_iaa, the calculated cpus_per_iaa will be 0, which causes a divide-by-0 in rebalance_wq_table(). Make sure cpus_per_iaa is 1 in that case, and also in the nr_iaa == 0 case, even though cpus_per_iaa is never used if nr_iaa == 0, for paranoia.