Preparation for 32 bit table IDs

Preparation for 32 bit table IDs

[IPROUTE]: Preparation for 32 bit table IDs

The route table filter uses an integer for the table number and the value
-1 to represent cloned routes. For 32 bit table IDs it needs to become an
unsigned, so this won't work anymore. Introduce a new filter flag "cloned"
and use instead of filter.tb = -1.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>