soc: bcm: brcmstb: Don't leak device tree node reference

of_find_node_by_path() acquires a reference to the node returned by it
and that reference needs to be dropped by its caller. soc_is_brcmstb()
doesn't do that, so fix it.

[treding: slightly rewrite to avoid inline comparison]

Fixes: d52fad26 ("soc: add stubs for brcmstb SoC's")
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

drivers/soc/bcm/brcmstb/common.c

@@ -31,13 +31,17 @@ static const struct of_device_id brcmstb_machine_match[] = {
 
 bool soc_is_brcmstb(void)
 {
+	const struct of_device_id *match;
 	struct device_node *root;
 
 	root = of_find_node_by_path("/");
 	if (!root)
 		return false;
 
-	return of_match_node(brcmstb_machine_match, root) != NULL;
+	match = of_match_node(brcmstb_machine_match, root);
+	of_node_put(root);
+
+	return match != NULL;
 }
 
 u32 brcmstb_get_family_id(void)