MFC r258821 - fix tcp simultaneous close

PR:             kern/99188


git-svn-id: svn+ssh://svn.freebsd.org/base/stable/7@260421 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Merged r260415 from head.

Approved by:	davidch


git-svn-id: svn+ssh://svn.freebsd.org/base/stable/7@260427 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Revert MFC of r258821 - it was already handled by MFC of r239672.

Pointy hat to: peter


git-svn-id: svn+ssh://svn.freebsd.org/base/stable/7@260437 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f