ocfs2: fix build failure when TCP/IP is disabled

ocfs2: fix build failure when TCP/IP is disabled

After commit ffe3774dd910 ("tcp: add tcp_sock_set_nodelay") and commit
e2f7f8046c9e ("tcp: add tcp_sock_set_user_timeout"), building the kernel
with OCFS2_FS=y but without INET=y causes it to fail with:

  ld: fs/ocfs2/cluster/tcp.o: in function `o2net_accept_many':
  tcp.c:(.text+0x21b1): undefined reference to `tcp_sock_set_nodelay'
  ld: tcp.c:(.text+0x21c1): undefined reference to `tcp_sock_set_user_timeout'
  ld: fs/ocfs2/cluster/tcp.o: in function `o2net_start_connect':
  tcp.c:(.text+0x2633): undefined reference to `tcp_sock_set_nodelay'
  ld: tcp.c:(.text+0x2643): undefined reference to `tcp_sock_set_user_timeout'

This is due to tcp_sock_set_nodelay() and tcp_sock_set_user_timeout()
being declared in linux/tcp.h and defined in net/ipv4/tcp.c, which
depend on TCP/IP being enabled.

To fix this, make OCFS2_FS depend on INET=y which already requires
NET=y.

Fixes: ffe3774dd910 ("tcp: add tcp_sock_set_nodelay")
Fixes: e2f7f8046c9e ("tcp: add tcp_sock_set_user_timeout")
Signed-off-by: Tom Seewald <tseewald@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Link: http://lkml.kernel.org/r/20200606190827.23954-1-tseewald@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>