powerpc: Lack of ibm,io-events not that important!

The ibm,io-events code is a bit verbose with its error messages.
Reverse the reporting so we only print when we successfully enable
I/O event interrupts.

Signed-off-by: Anton Blanchard <[e-mail]>
Signed-off-by: Benjamin Herrenschmidt <[e-mail]>

arch/powerpc/platforms/pseries/io_event_irq.c

···
 	struct device_node *np;
 
 	ioei_check_exception_token = rtas_token("check-exception");
-	if (ioei_check_exception_token == RTAS_UNKNOWN_SERVICE) {
-		pr_warning("IO Event IRQ not supported on this system !\n");
+	if (ioei_check_exception_token == RTAS_UNKNOWN_SERVICE)
 		return -ENODEV;
-	}
+
 	np = of_find_node_by_path("/event-sources/ibm,io-events");
 	if (np) {
 		request_event_sources_irqs(np, ioei_interrupt, "IO_EVENT");
+		pr_info("IBM I/O event interrupts enabled\n");
 		of_node_put(np);
 	} else {
-		pr_err("io_event_irq: No ibm,io-events on system! "
-		       "IO Event interrupt disabled.\n");
 		return -ENODEV;
 	}
 	return 0;