The current version of the TTY code unlocks the tty_struct(s) before
release_tty() rather than after.  Moreover, tty_unlock_pair() no longer
exists.  Thus, remove the outdated comments regarding tty_unlock_pair().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20200224073359.292795-1-ebiggers@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>