alpha: use __ratelimit

Replace open-coded rate limiting logic with __ratelimit().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: linux-alpha@vger.kernel.org
Signed-off-by: Matt Turner <mattst88@gmail.com>

arch/alpha/kernel/traps.c

@@ -17,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/kallsyms.h>
+#include <linux/ratelimit.h>
 
 #include <asm/gentrap.h>
 #include <asm/uaccess.h>
@@ -771,8 +772,7 @@ asmlinkage void
 do_entUnaUser(void __user * va, unsigned long opcode,
 	      unsigned long reg, struct pt_regs *regs)
 {
-	static int cnt = 0;
-	static unsigned long last_time;
+	static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
 
 	unsigned long tmp1, tmp2, tmp3, tmp4;
 	unsigned long fake_reg, *reg_addr = &fake_reg;
@@ -783,15 +783,11 @@ do_entUnaUser(void __user * va, unsigned long opcode,
 	   with the unaliged access.  */
 
 	if (!test_thread_flag (TIF_UAC_NOPRINT)) {
-		if (cnt >= 5 && time_after(jiffies, last_time + 5 * HZ)) {
-			cnt = 0;
-		}
-		if (++cnt < 5) {
+		if (__ratelimit(&ratelimit)) {
 			printk("%s(%d): unaligned trap at %016lx: %p %lx %ld\n",
 			       current->comm, task_pid_nr(current),
 			       regs->pc - 4, va, opcode, reg);
 		}
-		last_time = jiffies;
 	}
 	if (test_thread_flag (TIF_UAC_SIGBUS))
 		goto give_sigbus;