Fix: Kernel 4.10.0 got rid of an union

In kernel commit 2456e85535 was a cleanup where an union was removed.

See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2456e855354415bfaeb7badaa14e11b3e02c8466
and https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/diff/include/linux/futex.h?id=2456e855354415bfaeb7badaa14e11b3e02c8466
for further background information.

Reported-by: iysheng <iysheng@163.com>

Author: stappersg

module/tty0tty.c

@@ -228,7 +228,11 @@ static int tty0tty_write(struct tty_struct *tty, const unsigned char *buffer,
 	int retval = 0;
 	struct tty_struct *ttyx = NULL;
 	u64 elapsed, delay;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)
 	ktime_t start_time = ktime_get_ns();
+#else
+	u64 start_time = ktime_get_ns();
+#endif
 
 	if (!tty0tty)
 		return -ENODEV;