netlib_ipv6route.c: fix the issue of parsing IPv6 routing entries

Update the column ruler and field labels in route_ipv6_entry comment
to match the actual output: lowercase to uppercase, remove colons.
Consistent with Nuttx definition

Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>

Author: zhhyu7

netutils/netlib/netlib_ipv6route.c

@@ -49,14 +49,14 @@
 
 /* The form of the entry from the routing table file:
  *
- *            11111111112222222222333333333344444444445555
- *   12345678901234567890123456789012345678901234567890123
- *   nnnn. target:  xxxx:xxxx:xxxx:xxxxxxxx:xxxx:xxxx:xxxx
- *         netmask: xxxx:xxxx:xxxx:xxxxxxxx:xxxx:xxxx:xxxx
- *         router:  xxxx:xxxx:xxxx:xxxxxxxx:xxxx:xxxx:xxxx
+ *            1111111111222222222233333333334444444444555
+ *   1234567890123456789012345678901234567890123456789012
+ *   nnnn. TARGET  xxxx:xxxx:xxxx:xxxxxxxx:xxxx:xxxx:xxxx
+ *         NETMASK xxxx:xxxx:xxxx:xxxxxxxx:xxxx:xxxx:xxxx
+ *         ROUTER  xxxx:xxxx:xxxx:xxxxxxxx:xxxx:xxxx:xxxx
  */
 
-#define ADDR_OFFSET  15
+#define ADDR_OFFSET  14
 
 /****************************************************************************
  * Private Functions