ipv4: make ip_local_reserved_ports per netns

ip_local_port_range is already per netns, so should ip_local_reserved_ports
be. And since it is none by default we don't actually need it when we don't
enable CONFIG_SYSCTL.

By the way, rename inet_is_reserved_local_port() to inet_is_local_reserved_port()

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

diff --cc include/net/netns/ipv4.h
Simple merge

diff --cc kernel/sysctl.c
Simple merge

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

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

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

diff --cc net/ipv4/sysctl_net_ipv4.c
Simple merge

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

diff --cc net/sctp/socket.c
Simple merge