ASoC: tlv320aic32x4: Fix potential uninitialized variable

Fix compiler warning about uninitialized variable reported by
Stephen Rothwell <sfr@canb.auug.org.au>.
Signed-off-by: Annaliese McDermond <nh6z@nh6z.net>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/tlv320aic32x4-clk.c

@@ -82,7 +82,7 @@ static int clk_aic32x4_pll_get_muldiv(struct clk_aic32x4 *pll,
 	int ret;
 
 	ret = regmap_read(pll->regmap, AIC32X4_PLLPR, &val);
-	if (ret)
+	if (ret < 0)
 		return ret;
 	settings->r = val & AIC32X4_PLL_R_MASK;
 	settings->p = (val & AIC32X4_PLL_P_MASK) >> AIC32X4_PLL_P_SHIFT;