drm/msm: Ratelimit invalid-fence message

We have seen a couple cases where low memory situations cause something
bad to happen, followed by a flood of these messages obscuring the root
cause.  Lets ratelimit the dmesg spam so that next time it happens we
don't lose the kernel traces leading up to this.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>

drivers/gpu/drm/msm/msm_fence.c

@@ -45,7 +45,7 @@ int msm_wait_fence(struct msm_fence_context *fctx, uint32_t fence,
 	int ret;
 
 	if (fence > fctx->last_fence) {
-		DRM_ERROR("%s: waiting on invalid fence: %u (of %u)\n",
+		DRM_ERROR_RATELIMITED("%s: waiting on invalid fence: %u (of %u)\n",
 				fctx->name, fence, fctx->last_fence);
 		return -EINVAL;
 	}