pnpacpi: fix potential corruption on "pnpacpi: exceeded the max number of IRQ resources 2"

PNP_MAX_IRQ is 2
If a device invokes pnpacpi_parse_allocated_irqresource() 0, 1, or 2 times, we are happy.
The 3rd time, we will fail and print "pnpacpi: exceeded the max number of IRQ resources: 2"
The 4th and subsequent calls (if this ever happened) would silently scribble on
irq_resource[2], which doesn't actualy exist.

Found-by: Bjorn Helgaas <[e-mail]>
Signed-off-by: Len Brown <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/pnp/pnpacpi/rsparser.c

···
 	while (!(res->irq_resource[i].flags & IORESOURCE_UNSET) &&
 	       i < PNP_MAX_IRQ)
 		i++;
-	if (i >= PNP_MAX_IRQ && !warned) {
-		printk(KERN_WARNING "pnpacpi: exceeded the max number of IRQ "
-				"resources: %d \n", PNP_MAX_IRQ);
-		warned = 1;
+	if (i >= PNP_MAX_IRQ) {
+		if (!warned) {
+			printk(KERN_WARNING "pnpacpi: exceeded the max number"
+				" of IRQ resources: %d\n", PNP_MAX_IRQ);
+			warned = 1;
+		}
 		return;
 	}
 	/*