powerpc/85xx: p1022ds: Use NULL instead of 0 for pointers

The third argument for of_get_property() is a pointer, hence pass
NULL instead of 0.

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/platforms/85xx/p1022_ds.c

@@ -249,7 +249,7 @@ static void p1022ds_set_monitor_port(enum fsl_diu_monitor_port port)
 		goto exit;
 	}
 
-	iprop = of_get_property(law_node, "fsl,num-laws", 0);
+	iprop = of_get_property(law_node, "fsl,num-laws", NULL);
 	if (!iprop) {
 		pr_err("p1022ds: LAW node is missing fsl,num-laws property\n");
 		goto exit;