mtd: nand: omap: fix error-codes returned from omap-elm driver

This patch
 omap-elm.c: replaces -ve integer value returned during errorneous condition,
             with proper error-codes.
 omap-gpmc.c: updates omap-gpmc driver to pass error-codes returned from
             omap-elm driver to upper layers

Signed-off-by: Pekon Gupta <pekon@ti.com>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/drivers/mtd/nand/omap_elm.c b/drivers/mtd/nand/omap_elm.c
index afa629a..d963e6c 100644
--- a/drivers/mtd/nand/omap_elm.c
+++ b/drivers/mtd/nand/omap_elm.c
@@ -19,6 +19,7 @@
 #include <linux/mtd/omap_elm.h>
 #include <asm/arch/hardware.h>
 
+#define DRIVER_NAME		"omap-elm"
 #define ELM_DEFAULT_POLY (0)
 
 struct elm *elm_cfg;
@@ -113,8 +114,10 @@
 
 	/* check if correctable */
 	location_status = readl(&elm_cfg->error_location[poly].location_status);
-	if (!(location_status & ELM_LOCATION_STATUS_ECC_CORRECTABLE_MASK))
-		return -1;
+	if (!(location_status & ELM_LOCATION_STATUS_ECC_CORRECTABLE_MASK)) {
+		printf("%s: uncorrectable ECC errors\n", DRIVER_NAME);
+		return -EBADMSG;
+	}
 
 	/* get error count */
 	*error_count = readl(&elm_cfg->error_location[poly].location_status) &