vpxdec: handle non-display frames

Bug: 143115066
Test: bug repro steps
Change-Id: I4c581b229b83a555d6214075f0e5367d17461cc9
diff --git a/media/codec2/components/vpx/C2SoftVpxDec.h b/media/codec2/components/vpx/C2SoftVpxDec.h
index e51bcee..2065165 100644
--- a/media/codec2/components/vpx/C2SoftVpxDec.h
+++ b/media/codec2/components/vpx/C2SoftVpxDec.h
@@ -85,7 +85,7 @@
     status_t destroyDecoder();
     void finishWork(uint64_t index, const std::unique_ptr<C2Work> &work,
                     const std::shared_ptr<C2GraphicBlock> &block);
-    bool outputBuffer(
+    status_t outputBuffer(
             const std::shared_ptr<C2BlockPool> &pool,
             const std::unique_ptr<C2Work> &work);
     c2_status_t drainInternal(