powerpc/32: Add missing \n and switch to pr_warn()

The message is missing a \n, add it. Switch to pr_warn(), it's shorter
and less ugly.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/mm/init_32.c

@@ -137,7 +137,7 @@ void __init MMU_init(void)
 	if (memblock.memory.cnt > 1) {
 #ifndef CONFIG_WII
 		memblock_enforce_memory_limit(memblock.memory.regions[0].size);
-		printk(KERN_WARNING "Only using first contiguous memory region");
+		pr_warn("Only using first contiguous memory region\n");
 #else
 		wii_memory_fixups();
 #endif