Fix exceptions to copyright job

The exceptions list is processed into a form that excludes the given files or
directories from the `find` command that searches for files to scan. However,
a missing `-print` option caused the files to be included anyway (due to the
default action of the `find` command).
1 job for copyright-headers in 4 seconds (queued for 1 second)
Status Job ID Name Coverage
  Generate
passed #43778
cross
generate

00:00:04