ALSA: compress_core: integer overflow in snd_compr_allocate_buffer()

These are 32 bit values that come from the user, we need to check for
integer overflows or we could end up allocating a smaller buffer than
expected.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
static void snd_compr_update_tstamp(struct snd_compr_stream *stream,
		struct snd_compr_tstamp *tstamp)
{
	if (!stream->ops->pointer)
		return;
	stream->ops->pointer(stream, tstamp);
	pr_debug("dsp consumed till %d total %d bytes\n",
		tstamp->byte_offset, tstamp->copied_total);
	stream->runtime->hw_pointer = tstamp->byte_offset;
	stream->runtime->total_bytes_transferred = tstamp->copied_total;
}

static void snd_compr_update_tstamp(struct snd_compr_stream *stream,
		struct snd_compr_tstamp *tstamp)
{
	if (!stream->ops->pointer)
		return;
	stream->ops->pointer(stream, tstamp);
	pr_debug("dsp consumed till %d total %d bytes\n",
		tstamp->byte_offset, tstamp->copied_total);
	stream->runtime->hw_pointer = tstamp->byte_offset;
	stream->runtime->total_bytes_transferred = tstamp->copied_total;
}
