avoid exceeding commandline limits

don't use "zip -@" to read from stdin, as that expects one file per line
also zip doesn't like the dos-lineend, so strip that using tr

Change-Id: Ib5c9040a66390119aa7a46225f2d0c8f635bf39a
(cherry picked from commit d1cf36265d25ddee11e787c4c83692163b66b06b)
Reviewed-on: https://gerrit.libreoffice.org/13526
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>