doc/examples/vaapi_transcode: Simplify loop

Fixes: CID1428858(1/2) Logically dead code

Sponsored-by: Sovereign Tech Fund
Reviewed-by: "mypopy@gmail.com" <mypopy@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

doc/examples/vaapi_transcode.c

@@ -215,10 +215,8 @@ static int dec_enc(AVPacket *pkt, const AVCodec *enc_codec)
 
 fail:
         av_frame_free(&frame);
-        if (ret < 0)
-            return ret;
     }
-    return 0;
+    return ret;
 }
 
 int main(int argc, char **argv)