alpha: osf_sys: reduce kernel log spamming on invalid osf_mount call typenr

Calling the osf_mount system call with an invalid typenr value will
spam the kernel log with error messages. Reduce the spamming by making
it a ratelimited printk.  Issue found when exercising with the stress-ng
enosys system call stressor.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>

arch/alpha/kernel/osf_sys.c

@@ -522,7 +522,7 @@ SYSCALL_DEFINE4(osf_mount, unsigned long, typenr, const char __user *, path,
 		break;
 	default:
 		retval = -EINVAL;
-		printk("osf_mount(%ld, %x)\n", typenr, flag);
+		printk_ratelimited("osf_mount(%ld, %x)\n", typenr, flag);
 	}
 
 	return retval;