Update the manpage for openpty(3) to account for the recent fixes. Specifically, remove the BUGS section and note that openpty(3) now always does the various security-related steps.  Also, update the error return value section.  The PR below is for the original bug rather than the doc updates.
Update the manpage for openpty(3) to account for the recent fixes.
Specifically, remove the BUGS section and note that openpty(3) now always
does the various security-related steps.  Also, update the error return
value section.  The PR below is for the original bug rather than the doc
updates.

MFC after:	1 week
PR:		bin/9770

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase