zebra: use AF_INET for protocol family

zebra: use AF_INET for protocol family

When looking up the conversion from kernel protocol to
internal protocol family make sure we use the correct
AF_INET( what the kernel uses ) instead of AFI_IP (which
is what FRR uses ).

Routes from OSPF will show up from the kernel as OSPF6 instead of
OSPF.  Which will cause mayhem

Ticket: CM-33306
Signed-off-by: Donald Sharp <sharpd@nvidia.com>