roqaudioenc: remove dead code

Fixes CID703669
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/roqaudioenc.c

@@ -168,7 +168,7 @@ static int roq_dpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
         context->lastSample[1] &= 0xFF00;
     }
 
-    if (context->input_frames == 7 || !in)
+    if (context->input_frames == 7)
         data_size = avctx->channels * context->buffered_samples;
     else
         data_size = avctx->channels * avctx->frame_size;