canxl extension: use plain union instead of typedef

"In general, a pointer, or a struct that has elements that can reasonably
be directly accessed should never be a typedef."

https://www.kernel.org/doc/html/v5.0/process/coding-style.html#typedefs

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>

log2long.c

@@ -68,7 +68,7 @@
 int main(void)
 {
 	static char buf[BUFSZ], timestamp[TIMESZ], device[DEVSZ], afrbuf[AFRSZ];
-	static cu_t cu;
+	static union cfu cu;
 	int mtu;
 
 	while (fgets(buf, BUFSZ-1, stdin)) {