For consistency with other implementations, check for the existence of the segment before checking its permissions.
For consistency with other implementations, check for the existence
of the segment before checking its permissions.

PR:		kern/11999
Submitted by:	Brooks Davis <brooks@one-eyed-alien.net>

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