drm/amdgpu: fix sdma_v2_4_ring_test_ib

Typo in checking the return code.

Signed-off-by: Christian König <[e-mail]>
Reviewed-by: Alex Deucher <[e-mail]>
Reviewed-by: Chunming Zhou <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/sdma_v2_4.c

···
 		DRM_ERROR("amdgpu: IB test timed out\n");
 		r = -ETIMEDOUT;
 		goto err1;
-	} else if (r) {
+	} else if (r < 0) {
 		DRM_ERROR("amdgpu: fence wait failed (%ld).\n", r);
 		goto err1;
 	}