dfu: nand: Verify writes

Previously NAND writes were not verified and could fail silently.  Add
a verification step after all writes to NAND.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
Tested-by: Heiko Schocher <hs@denx.de>
Acked-by: Heiko Schocher <hs@denx.de>

drivers/dfu/dfu_nand.c

@@ -64,7 +64,7 @@ static int nand_block_op(enum dfu_op op, struct dfu_entity *dfu,
 			return ret;
 		/* then write */
 		ret = nand_write_skip_bad(nand, start, &count, &actual,
-				lim, buf, 0);
+				lim, buf, WITH_WR_VERIFY);
 	}
 
 	if (ret != 0) {