drm/amd/display: fix a Null pointer dereference vulnerability

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: fix a Null pointer dereference vulnerability [Why] A null pointer dereference vulnerability exists in the AMD display driver's (DC module) cleanup function dc_destruct(). When display control context (dc->ctx) construction fails (due to memory allocation failure), this pointer remains NULL. During subsequent error handling when dc_destruct() is called, there's no NULL check before dereferencing the perf_trace member (dc->ctx->perf_trace), causing a kernel null pointer dereference crash. [How] Check if dc->ctx is non-NULL before dereferencing. (Updated commit text and removed unnecessary error message) (cherry picked from commit 9dd8e2ba268c636c240a918e0a31e6feaee19404)

An out of bounds write in the Linux graphics driver could allow an attacker to overflow the buffer potentially resulting in loss of confidentiality, integrity, or availability.