zebra: fix a crash in static_add_ipv6 caused by a NULL dereference

si will be NULL after end of the preceeding for loop. update is the
right static route info to use for deleting the old route.

Signed-off-by: Christian Franke <chris@opensourcerouting.org>
Signed-off-by: Christian Franke <chris@opensourcerouting.org>
Tested-by: NetDEF CI System <cisystem@netdef.org>
Acked-by: Donald Sharp <sharpd@cumulusnetworks.com>
1 file changed