selftests/tcp_ao: Fix printing format for uint64_t

selftests/tcp_ao: Fix printing format for uint64_t

It's not safe to use '%zu' specifier for printing uint64_t on 32-bit
systems. For uint64_t, we should use the 'PRIu64' macro from
the inttypes.h library. This ensures that the uint64_t is printed
correctly from the selftests regardless of the system architecture.

Signed-off-by: Mohammad Nassiri <mnassiri@ciena.com>
[Added missing spaces in fail/ok messages and uint64_t cast in
 setsockopt-closed, as otherwise it was giving warnings on 64bit.
 And carried it to netdev ml]
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://patch.msgid.link/20240823-tcp-ao-selftests-upd-6-12-v4-6-05623636fe8c@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>