zebra/ospf/ospf6: Fix several memory leaks on if up/down

zebra/ospf/ospf6: Fix several memory leaks on if up/down

Resolved several memory leaks caused by ifdown/ifup the vrf device or
a swp port.  For bgp/zebra/ospf/ospf6, bouncing the vrf device would cause
a linked list, Interface, and route-table to get leaked.  For ospf6,
bouncing the swp device also caused leaks of Connected and Prefix entries.

Ticket: CM-10841
Signed-off-by: Don Slice
Reviewed-By: Donald Sharp
Testing Done: Manual testing, bgp and ospf mins passed, smokes had fewer failures than base