Fix parallel build race failure.

Sometimes building in parallel will fail in the pdfmark directory:

  make[2]: Entering directory '.../contrib/pdfmark'
  rm -f pdfroff
  rm -f pdfmark.pdf
  sed -f ... ./pdfroff.sh >pdfroff
  ...; ./pdfroff ... pdfmark.ms >pdfmark.pdf
  /bin/sh: ./pdfroff: Permission denied
  chmod +x pdfroff
  make[2]: *** [pdfmark.pdf] Error 126

This is because the generated pdf files use the local generated
pdfroff helper script, but they don't depend directly upon it, so
make tries to create the two in parallel and randomly falls over.

* Makefile.sub: Have all the .pdf files explicitly depend on the
`pdfroff' helper script.

0 files changed, 0 insertions, 0 deletions