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 <Prike.Liang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -800,6 +800,7 @@ int amdgpu_acpi_power_shift_control(struct amdgpu_device *adev,
 		return -EIO;
 	}
 
+	kfree(info);
 	return 0;
 }