net: Fix a data-race around sysctlnetbusy_read.
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 v5.4.212 by commit 575c57e9e00cb321b7efd162cf9554dec05ad5fe, it was introduced in version v3.11 by commit 2d48d67fa8cd129ea85ea02d91b4a793286866f8. For more details please see the references link.