ipv4: Fix nexthop caching wrt. scoping.

Move the scope value out of the fib alias entries and into fib_info,
so that we always use the correct scope when recomputing the nexthop
cached source address.

Reported-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc include/net/ip_fib.h
Simple merge

diff --cc net/ipv4/fib_lookup.h
Simple merge

diff --cc net/ipv4/fib_semantics.c
Simple merge

diff --cc net/ipv4/fib_trie.c
Simple merge