Make dhclient-script more agreeable with read-only /etc.
Make dhclient-script more agreeable with read-only /etc.

PR:		90518
Submitted by:	John E. Hein <jhein@timing.com>
MFC after:	3 days

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