GSD-2022-1003873 dlm: fix plock invalid read

dlm: fix plock invalid 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 v4.19.247 by commit 5a1765adf9855cf0f6d3f7e0eb4b78ca66f70dee, it was...