Instead of using atomic_inc(), prefer fib6_info_hold()
so that upcoming refcount_t conversion is simpler.
Only fib6_info_alloc() is using atomic_set() since we
just allocated a new object.
Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Wei Wang <weiwan@google.com> Acked-by: Wei Wang <weiwan@google.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>