ALSA: memalloc: invalidate SG pages before sync

It seems that calling invalidate_kernel_vmap_range() is more correct
to be called before dma_sync_*(), judging from the other thread:
  https://lore.kernel.org/all/20220111085958.GA22795@lst.de/


Although this won't matter much in practice, let's fix the call order
for consistency.

Fixes: a25684a9 ("ALSA: memalloc: Support for non-contiguous page allocation")
Reported-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220210123344.8756-3-tiwai@suse.de


Signed-off-by: Takashi Iwai <tiwai@suse.de>