drm/amdgpu: Dereference the ATCS ACPI buffer

Need to dereference the atcs acpi buffer after
the method is executed, otherwise it will result in
a memory leak.

Signed-off-by: Prike Liang <[e-mail]>
Reviewed-by: Alex Deucher <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c

···
 		return -EIO;
 	}
 
+	kfree(info);
 	return 0;
 }