net: Refactor rtable initialization
net: Refactor rtable initialization

All callers to rt_dst_alloc have nearly the same initialization following
a successful allocation. Consolidate it into rt_dst_alloc.

Signed-off-by: David Ahern <e908389d4bbf30e8dc72dc47cdf6b45d89e8b2a0@cumulusnetworks.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs