drm/amdgpu: drop the critial WARN_ON in amdgpu_vkms

Signed-off-by: Flora Cui <flora.cui@amd.com>
Reviewed-by: Leslie Shi <Yuliang.Shi@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_vkms.c

@@ -51,7 +51,8 @@ static enum hrtimer_restart amdgpu_vkms_vblank_simulate(struct hrtimer *timer)
 
 	ret_overrun = hrtimer_forward_now(&amdgpu_crtc->vblank_timer,
 					  output->period_ns);
-	WARN_ON(ret_overrun != 1);
+	if (ret_overrun != 1)
+		DRM_WARN("%s: vblank timer overrun\n", __func__);
 
 	ret = drm_crtc_handle_vblank(crtc);
 	if (!ret)