mfd: lp8788: Fix an error handling path in lp8788_probe()

Should an error occurs in mfd_add_devices(), some resources need to be
released, as already done in the .remove() function.

Add an error handling path and a lp8788_irq_exit() call to undo a previous
lp8788_irq_init().

Fixes: eea6b7cc ("mfd: Add lp8788 mfd driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/18398722da9df9490722d853e4797350189ae79b.1659261275.git.christophe.jaillet@wanadoo.fr

drivers/mfd/lp8788.c

@@ -195,8 +195,16 @@ static int lp8788_probe(struct i2c_client *cl, const struct i2c_device_id *id)
 	if (ret)
 		return ret;
 
-	return mfd_add_devices(lp->dev, -1, lp8788_devs,
-			       ARRAY_SIZE(lp8788_devs), NULL, 0, NULL);
+	ret = mfd_add_devices(lp->dev, -1, lp8788_devs,
+			      ARRAY_SIZE(lp8788_devs), NULL, 0, NULL);
+	if (ret)
+		goto err_exit_irq;
+
+	return 0;
+
+err_exit_irq:
+	lp8788_irq_exit(lp);
+	return ret;
 }
 
 static int lp8788_remove(struct i2c_client *cl)