ARM: exynos: Fix a leaked reference by adding missing of_node_put

The call to of_get_next_child returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.

Detected by coccinelle with warnings like:
    arch/arm/mach-exynos/firmware.c:201:2-8: ERROR: missing of_node_put;
        acquired a node pointer with refcount incremented on line 193,
        but without a corresponding object release within this function.

Cc: stable@vger.kernel.org
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

arch/arm/mach-exynos/firmware.c

@@ -196,6 +196,7 @@ bool __init exynos_secure_firmware_available(void)
 		return false;
 
 	addr = of_get_address(nd, 0, NULL, NULL);
+	of_node_put(nd);
 	if (!addr) {
 		pr_err("%s: No address specified.\n", __func__);
 		return false;

arch/arm/mach-exynos/suspend.c

@@ -669,8 +669,10 @@ void __init exynos_pm_init(void)
 
 	if (WARN_ON(!of_find_property(np, "interrupt-controller", NULL))) {
 		pr_warn("Outdated DT detected, suspend/resume will NOT work\n");
+		of_node_put(np);
 		return;
 	}
+	of_node_put(np);
 
 	pm_data = (const struct exynos_pm_data *) match->data;