x86/cpu: Convert printk(KERN_<LEVEL> ...) to pr_<level>(...)

- Use the more current logging style pr_<level>(...) instead of the old
   printk(KERN_<LEVEL> ...).

 - Convert pr_warning() to pr_warn().

Signed-off-by: Chen Yucong <slaoub@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1454384702-21707-1-git-send-email-slaoub@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/rdrand.c

@@ -51,7 +51,7 @@ void x86_init_rdrand(struct cpuinfo_x86 *c)
 	for (i = 0; i < SANITY_CHECK_LOOPS; i++) {
 		if (!rdrand_long(&tmp)) {
 			clear_cpu_cap(c, X86_FEATURE_RDRAND);
-			printk_once(KERN_WARNING "rdrand: disabled\n");
+			pr_warn_once("rdrand: disabled\n");
 			return;
 		}
 	}