every even numbered print job is reported as failed

because of.
bool bSuccess;
...
bSuccess &= ...endSpool(...);

in PspSalPrinter::StartJob

was...

endSpool return value is effectively success flag, not job ID

(cherry picked from commit e6323214830895d1c76ec44ee53990bf577fbda2)

Change-Id: I5b96eeff80ca29f0f8f24ee6da7a2ca76cbb05ce
Reviewed-on: https://gerrit.libreoffice.org/9093
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>