ALSA: dmaengine_pcm: No need to take runtime reference twice in pcm_pointer

The runtime pointer has been taken in functional level so there is no need
to take it again under the if () case.

Fixes: 9d789dc047 ("ALSA: dmaengine_pcm: Consider DMA cache caused delay in pointer callback")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200227093544.27723-1-peter.ujfalusi@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/core/pcm_dmaengine.c

@@ -248,8 +248,6 @@ snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
 
 	status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
 	if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
-		struct snd_pcm_runtime *runtime = substream->runtime;
-
 		buf_size = snd_pcm_lib_buffer_bytes(substream);
 		if (state.residue > 0 && state.residue <= buf_size)
 			pos = buf_size - state.residue;