CVE-2022-49634 sysctl: Fix data-races in proc_dou8vec_minmax().

In the Linux kernel, the following vulnerability has been resolved: sysctl: Fix data-races in procdou8vecminmax. A sysctl variable is accessed concurrently, and there is always a chance of data-race. So, all readers and writers need some basic protection to avoid load/store-tearing. This patch...