Use the correct flags (IO_SYNC -> B_SYNC) when deciding to do a sync or async write in the section that changes the filesize. The bug resulted in the updates always being async.
Use the correct flags (IO_SYNC -> B_SYNC) when deciding to do a sync or
async write in the section that changes the filesize. The bug resulted
in the updates always being async.

Obtained from:	4.4BSD-Lite2

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