soc: aspeed: Fix a reference leak in aspeed_socinfo_init()

This needs to call of_node_put(np) before returning if of_iomap() fails.

Fixes: e0218dca ("soc: aspeed: Add soc info driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20201113100850.GA168908@mwandaSigned-off-by: Joel Stanley <joel@jms.id.au>

drivers/soc/aspeed/aspeed-socinfo.c

@@ -74,8 +74,10 @@ static int __init aspeed_socinfo_init(void)
 	}
 
 	reg = of_iomap(np, 0);
-	if (!reg)
+	if (!reg) {
+		of_node_put(np);
 		return -ENODEV;
+	}
 	siliconid = readl(reg);
 	iounmap(reg);