net: Fix a data-race around sysctlnetbusy_poll.
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v4.19.257 by commit da89cab514b3ec7fdedb378617160c47fe3b60a9, it was introduced in version v3.11 by commit 060212928670593fb89243640bf05cf89560b023. For more details please see the references link.