wandboard: Fix error handling in board_mmc_init()

When an invalid USDHC port is passed we should return -EINVAL instead of 0.

Also, return the error immediately on fsl_esdhc_initialize() failure.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/board/wandboard/wandboard.c b/board/wandboard/wandboard.c
index 3c8b7a5..1075c65 100644
--- a/board/wandboard/wandboard.c
+++ b/board/wandboard/wandboard.c
@@ -144,7 +144,7 @@
 
 int board_mmc_init(bd_t *bis)
 {
-	s32 status = 0;
+	int ret;
 	u32 index = 0;
 
 	/*
@@ -173,13 +173,15 @@
 			printf("Warning: you configured more USDHC controllers"
 			       "(%d) then supported by the board (%d)\n",
 			       index + 1, CONFIG_SYS_FSL_USDHC_NUM);
-			return status;
+			return -EINVAL;
 		}
 
-		status |= fsl_esdhc_initialize(bis, &usdhc_cfg[index]);
+		ret = fsl_esdhc_initialize(bis, &usdhc_cfg[index]);
+		if (ret)
+			return ret;
 	}
 
-	return status;
+	return 0;
 }
 
 static int mx6_rgmii_rework(struct phy_device *phydev)