The NULL check can be done gracefully without cast.  It fixes a
compile warning like:
  sound/soc/bcm/bcm63xx-pcm-whistler.c:184:6: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
Fixes: 88eb404ccc3e ("ASoC: brcm: Add DSL/PON SoC audio driver")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20200330135645.9707-1-tiwai@suse.de
Signed-off-by: Mark Brown <broonie@kernel.org>
        snd_pcm_uframes_t x;
        struct bcm63xx_runtime_data *prtd = substream->runtime->private_data;
 
-       if ((void *)prtd->dma_addr_next == NULL)
+       if (!prtd->dma_addr_next)
                prtd->dma_addr_next = substream->runtime->dma_addr;
 
        x = bytes_to_frames(substream->runtime,