[MTD NAND] Fix lookup error in nand_get_flash_type()

Spotted by liyu <liyu@ccoss.com.cn>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index cffd663..119d17c 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2222,7 +2222,7 @@
 	}
 
 	/* Try to identify manufacturer */
-	for (maf_idx = 0; nand_manuf_ids[maf_idx].id != 0x0; maf_id++) {
+	for (maf_idx = 0; nand_manuf_ids[maf_idx].id != 0x0; maf_idx++) {
 		if (nand_manuf_ids[maf_idx].id == *maf_id)
 			break;
 	}