netinet: The tailq_hash code doesn't reference tcpoutflags

Don't define TCPOUTFLAGS to get the static definition from tcp_fsm.h.
tailq_hash.c doesn't refernce tcpoutflag. Only files that reference this
should define TCPOUTFLAGS. clang is fine with it, but gcc12 complained.

Sponsored by: Netflix

(cherry picked from commit afd155c72bf65c056d19473569cc78c6e5807b3b)