Restore spares used in "struct tcpcb" and bump "__FreeBSD_version" to
indicate need for kernel module re-compilation.

Sponsored by:	Mellanox Technologies


git-svn-id: svn+ssh://svn.freebsd.org/base/head@274046 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Clarify TSO segment limit comment and remove two TABs to make lines a
bit shorter.

Sponsored by:	Mellanox Technologies


git-svn-id: svn+ssh://svn.freebsd.org/base/head@274047 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Fix misplaced read memory barrier in seq.

Impact on capability races was small: it was possible to get a spurious
ENOTCAPABLE (early return), but it was not possible to bypass checks.

Tidy up some comments.


git-svn-id: svn+ssh://svn.freebsd.org/base/head@274048 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f