powerpc/embedded6xx/ls_uart: Add missing of_node_put()

In ls_uarts_init(), add an of_node_put() to keep refcount balance.
Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220620065904.4071787-1-windhl@126.com

arch/powerpc/platforms/embedded6xx/ls_uart.c

@@ -124,6 +124,8 @@ static int __init ls_uarts_init(void)
 	avr_clock = *(u32*)of_get_property(avr, "clock-frequency", &len);
 	phys_addr = ((u32*)of_get_property(avr, "reg", &len))[0];
 
+	of_node_put(avr);
+
 	if (!avr_clock || !phys_addr)
 		return -EINVAL;