tcp: Add selftest for bind() and TIME_WAIT.

bhash2 split the bind() validation logic into wildcard and non-wildcard
cases. Let's add a test to catch future regression.

Before the previous patch:

# ./bind_timewait
TAP version 13
1..2
# Starting 2 tests from 3 test cases.
# RUN bind_timewait.localhost.1 ...
# bind_timewait.c:87:1:Expected ret (0) == -1 (-1)
# 1: Test terminated by assertion
# FAIL bind_timewait.localhost.1
not ok 1 bind_timewait.localhost.1
# RUN bind_timewait.addrany.1 ...
# OK bind_timewait.addrany.1
ok 2 bind_timewait.addrany.1
# FAILED: 1 / 2 tests passed.
# Totals: pass:1 fail:1 xfail:0 xpass:0 skip:0 error:0

After:

# ./bind_timewait
TAP version 13
1..2
# Starting 2 tests from 3 test cases.
# RUN bind_timewait.localhost.1 ...
# OK bind_timewait.localhost.1
ok 1 bind_timewait.localhost.1
# RUN bind_timewait.addrany.1 ...
# OK bind_timewait.addrany.1
ok 2 bind_timewait.addrany.1
# PASSED: 2 / 2 tests passed.
# Totals: pass:2 fail:0 xfail:0 xpass:0 skip:0 error:0

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>