GCC4.6: Squash warnings in onenand_base.c

Fix gcc 4.6 build warnings:
onenand_base.c: In function 'onenand_probe':
onenand_base.c:2577:6: warning: variable 'maf_id' set but not used
[-Wunused-but-set-variable]

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>

drivers/mtd/onenand/onenand_base.c

@@ -2574,7 +2574,7 @@ static int onenand_chip_probe(struct mtd_info *mtd)
 int onenand_probe(struct mtd_info *mtd)
 {
 	struct onenand_chip *this = mtd->priv;
-	int maf_id, dev_id, ver_id;
+	int dev_id, ver_id;
 	int density;
 	int ret;
 
@@ -2582,8 +2582,7 @@ int onenand_probe(struct mtd_info *mtd)
 	if (ret)
 		return ret;
 
-	/* Read manufacturer and device IDs from Register */
-	maf_id = this->read_word(this->base + ONENAND_REG_MANUFACTURER_ID);
+	/* Read device IDs from Register */
 	dev_id = this->read_word(this->base + ONENAND_REG_DEVICE_ID);
 	ver_id = this->read_word(this->base + ONENAND_REG_VERSION_ID);
 	this->technology = this->read_word(this->base + ONENAND_REG_TECHNOLOGY);