mfd: ucb1x00-core: Fix error return code in ucb1x00_probe()

Fix to return a negative error code in the irq alloc error handling
case instead of 0, as done elsewhere in this function.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

drivers/mfd/ucb1x00-core.c

@@ -553,6 +553,7 @@ static int ucb1x00_probe(struct mcp *mcp)
 	if (ucb->irq_base < 0) {
 		dev_err(&ucb->dev, "unable to allocate 16 irqs: %d\n",
 			ucb->irq_base);
+		ret = ucb->irq_base;
 		goto err_irq_alloc;
 	}