of/irq: Fix of_irq_parse_one() returned error codes

commit d7c14605 upstream.

The error code paths that require cleanup use a goto to jump to the
cleanup code and return an error code. However, the error code variable
res, which is initialized to -EINVAL when declared, is then overwritten
with the return value of of_parse_phandle_with_args(), and reused as the
return code from of_irq_parse_one(). This leads to an undetermined error
being returned instead of the expected -EINVAL value. Fix it.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/of/irq.c

@@ -290,7 +290,7 @@ int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_ar
 	struct device_node *p;
 	const __be32 *intspec, *tmp, *addr;
 	u32 intsize, intlen;
-	int i, res = -EINVAL;
+	int i, res;
 
 	pr_debug("of_irq_parse_one: dev=%s, index=%d\n", of_node_full_name(device), index);
 
@@ -323,15 +323,19 @@ int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_ar
 
 	/* Get size of interrupt specifier */
 	tmp = of_get_property(p, "#interrupt-cells", NULL);
-	if (tmp == NULL)
+	if (tmp == NULL) {
+		res = -EINVAL;
 		goto out;
+	}
 	intsize = be32_to_cpu(*tmp);
 
 	pr_debug(" intsize=%d intlen=%d\n", intsize, intlen);
 
 	/* Check index */
-	if ((index + 1) * intsize > intlen)
+	if ((index + 1) * intsize > intlen) {
+		res = -EINVAL;
 		goto out;
+	}
 
 	/* Copy intspec into irq structure */
 	intspec += index * intsize;