media/gpu: V4L2SVD: fix condition error in SetupOutputFormat.

BUG=chromium:979115
TEST=run video_decode_accelerator_tests --use_vd on Kevin

Change-Id: I97ed910d7f94ea146ee75aa776b2aad1b62116a8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1720110Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Commit-Queue: Chih-Yu Huang <akahuang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#681177}

media/gpu/v4l2/v4l2_slice_video_decoder.cc

@@ -463,7 +463,7 @@ base::Optional<VideoFrameLayout> V4L2SliceVideoDecoder::SetupOutputFormat(
                             frame_layout->coded_size().height());
     base::Optional<struct v4l2_format> format =
         SetFormatOnOutputQueue(format_fourcc, adjusted_size);
-    if (!format) {
+    if (format) {
       num_output_planes_ = format->fmt.pix_mp.num_planes;
       return frame_layout;
     }