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 <[e-mail]>
Signed-off-by: Matt Turner <[e-mail]>

arch/alpha/kernel/osf_sys.c

···
 		break;
 	default:
 		retval = -EINVAL;
-		printk("osf_mount(%ld, %x)\n", typenr, flag);
+		printk_ratelimited("osf_mount(%ld, %x)\n", typenr, flag);
 	}
 
 	return retval;