Switch the default I/O memory barrier to eieio, as it should be. This does not appear to cause any problems due to fixes elsewhere.
Switch the default I/O memory barrier to eieio, as it should be. This
does not appear to cause any problems due to fixes elsewhere.

MFC after:	2 months

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