Since we do not plan using pthread_join() in the server do_accept()
loop, we better create detached threads, or risk increasing memory
footprint over time.
Fixes: 192dc405f308 ("selftests: net: add tcp_mmap program") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>