kontron-pitx-imx8m: fix board_mmc_getcd()

The function wrongly will return the card detection status of the SD card
(USDHC2) for the eMMC (USDHC1). Thus booting from eMMC without an inserted
SD card will fail.

Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
diff --git a/board/kontron/pitx_imx8m/spl.c b/board/kontron/pitx_imx8m/spl.c
index c043dd2..ef32568 100644
--- a/board/kontron/pitx_imx8m/spl.c
+++ b/board/kontron/pitx_imx8m/spl.c
@@ -76,17 +76,16 @@
 int board_mmc_getcd(struct mmc *mmc)
 {
 	struct fsl_esdhc_cfg *cfg = (struct fsl_esdhc_cfg *)mmc->priv;
-	int ret = 0;
 
 	switch (cfg->esdhc_base) {
 	case USDHC1_BASE_ADDR:
 		/* the eMMC does not have a CD pin */
-		ret = 1;
+		return 1;
 	case USDHC2_BASE_ADDR:
-		ret = !gpio_get_value(USDHC2_CD_GPIO);
+		return !gpio_get_value(USDHC2_CD_GPIO);
 	}
 
-	return ret;
+	return 0;
 }