drm/amdgpu: Fix memory leak in amdgpu_ras_init()

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix memory leak in amdgpu_ras_init() When amdgpu_nbio_ras_sw_init() fails in amdgpu_ras_init(), the function returns directly without freeing the allocated con structure, leading to a memory leak. Fix this by jumping to the release_con label to properly clean up the allocated memory before returning the error code. Compile tested only. Issue found using a prototype static analysis tool and code review.