selftests/net: fix warnings on reuseaddr_ports_exhausted

Fix multiple warnings seen with gcc 10.2.1:
reuseaddr_ports_exhausted.c:32:41: warning: missing braces around initializer [-Wmissing-braces]
32 | struct reuse_opts unreusable_opts[12] = {
| ^
33 | {0, 0, 0, 0},
| { } { }

Fixes: 7f204a7de8b0 ("selftests: net: Add SO_REUSEADDR test to check if 4-tuples are fully utilized.")
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests: net: Add SO_REUSEADDR test to check if 4-tuples are fully utilized.

This commit adds a test to check if we can fully utilize 4-tuples for
connect() when all ephemeral ports are exhausted.

The test program changes the local port range to use only one port and binds
two sockets with or without SO_REUSEADDR and SO_REUSEPORT, and with the same
EUID or with different EUIDs, then do listen().

We should be able to bind only one socket having both SO_REUSEADDR and
SO_REUSEPORT per EUID, which restriction is to prevent unintentional
listen().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>