Fix oversight in recent pg_basebackup fix causing pg_receivexlog failures.

A oversight in 2c0a4858 causes 'could not create archive status file
"...": No such file or directory' errors in pg_receivexlog if the
target directory doesn't happen to contain a archive_status
directory. That's due to a stupidly left over 'true' constant instead
of mark_done being passed down to ProcessXLogDataMsg().

The bug is only present in the master branch, and luckily wasn't
released.

Spotted by Fujii Masao.