archbuild: Fix a variable name mistake. ($copydir -> $copy)

It tried to lock `$copydir.lock`, which was the ONLY mention of $copydir in
the entire file.  Surely it meant `$copy.lock`; the line was probably
originally copy/pasted from makechrootpkg or similar, where $copydir is
used.

0 files changed, 0 insertions, 0 deletions