ASoC: sun4i-i2s: Replace call to params_channels by local variable

The sun4i_i2s_hw_params already has a variable holding the value returned
by params_channels, so let's just use that variable instead of calling
params_channels multiple times.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://lore.kernel.org/r/c0faaac69ad40248f24eed3c3b2fa1ccc4a85b70.1566242458.git-series.maxime.ripard@bootlin.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sunxi/sun4i-i2s.c

@@ -412,10 +412,9 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream,
 
 	/* Configure the channels */
 	regmap_field_write(i2s->field_txchansel,
-			   SUN4I_I2S_CHAN_SEL(params_channels(params)));
-
+			   SUN4I_I2S_CHAN_SEL(channels));
 	regmap_field_write(i2s->field_rxchansel,
-			   SUN4I_I2S_CHAN_SEL(params_channels(params)));
+			   SUN4I_I2S_CHAN_SEL(channels));
 
 	if (i2s->variant->has_chsel_tx_chen)
 		regmap_update_bits(i2s->regmap, SUN8I_I2S_TX_CHAN_SEL_REG,