gsmi: fix null-deref in gsmigetvariable
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 v6.1.8 by commit 6646d769fdb0ce4318ef9afd127f8526d1ca8393, it was introduced in version v3.0 by commit 74c5b31c6618f01079212332b2e5f6c42f2d6307. For more details please see the references link.