tcp_memcontrol: Kill struct tcp_memcontrol

Replace the pointers in struct cg_proto with actual data fields and kill
struct tcp_memcontrol as it is not fully redundant.

This removes a confusing, unnecessary layer of abstraction.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

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

diff --cc mm/memcontrol.c
Simple merge

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