microblaze: Fix coding style issues

Fix coding style issues reported by checkpatch.pl.

Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/kernel/heartbeat.c b/arch/microblaze/kernel/heartbeat.c
index 154756f..1879a05 100644
--- a/arch/microblaze/kernel/heartbeat.c
+++ b/arch/microblaze/kernel/heartbeat.c
@@ -61,7 +61,7 @@
 	if (gpio) {
 		base_addr = be32_to_cpup(of_get_property(gpio, "reg", NULL));
 		base_addr = (unsigned long) ioremap(base_addr, PAGE_SIZE);
-		printk(KERN_NOTICE "Heartbeat GPIO at 0x%x\n", base_addr);
+		pr_notice("Heartbeat GPIO at 0x%x\n", base_addr);
 
 		/* GPIO is configured as output */
 		prop = (int *) of_get_property(gpio, "xlnx,is-bidir", NULL);