of/irq: Refer to actual buffer size in of_irq_parse_one()

Replace two open-coded calculations of the buffer size by invocations of
sizeof() on the buffer itself, to make sure the code will always use the
actual buffer size.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/817c0b9626fd30790fc488c472a3398324cfcc0c.1724156125.git.geert+renesas@glider.beSigned-off-by: Rob Herring (Arm) <robh@kernel.org>

drivers/of/irq.c

@@ -357,8 +357,8 @@ int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_ar
 	addr = of_get_property(device, "reg", &addr_len);
 
 	/* Prevent out-of-bounds read in case of longer interrupt parent address size */
-	if (addr_len > (3 * sizeof(__be32)))
-		addr_len = 3 * sizeof(__be32);
+	if (addr_len > sizeof(addr_buf))
+		addr_len = sizeof(addr_buf);
 	if (addr)
 		memcpy(addr_buf, addr, addr_len);