ARM: perf: use pr_* instead of printk

There are a few remaining uses of printk in the ARM perf code, so move
them over to the pr_* variants instead.

Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm/kernel/perf_event_cpu.c

@@ -120,7 +120,7 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
 
 	irqs = min(pmu_device->num_resources, num_possible_cpus());
 	if (irqs < 1) {
-		printk_once("perf/ARM: No irqs for PMU defined, sampling events not supported\n");
+		pr_warn_once("perf/ARM: No irqs for PMU defined, sampling events not supported\n");
 		return 0;
 	}