oven: Fix temporary file usage
oven: Fix temporary file usage

tmp only exists fi self.missing_files is True

flexVDI/cerbero,freedesktop-unofficial-mirror/gstreamer__cerbero,sdroege/cerbero,AlertMe/cerbero,justinjoy/cerbero,freedesktop-unofficial-mirror/gstreamer__cerbero,EricssonResearch/cerbero,jackjansen/cerbero,multipath-rtp/cerbero,nirbheek/cerbero,OptoFidelity/cerbero,flexVDI/cerbero,jackjansen/cerbero,EricssonResearch/cerbero,atsushieno/cerbero,fluendo/cerbero,ramaxlo/cerbero,superdump/cerbero,nzjrs/cerbero,sdroege/cerbero,EricssonResearch/cerbero,nzjrs/cerbero,freedesktop-unofficial-mirror/gstreamer__sdk__cerbero,nirbheek/cerbero-old,fluendo/cerbero,ikonst/cerbero,nzjrs/cerbero,sdroege/cerbero,centricular/cerbero,brion/cerbero,nirbheek/cerbero,shoreflyer/cerbero,ford-prefect/cerbero,fluendo/cerbero,fluendo/cerbero,nirbheek/cerbero-old,AlertMe/cerbero,shoreflyer/cerbero,shoreflyer/cerbero,centricular/cerbero,atsushieno/cerbero,jackjansen/cerbero,OptoFidelity/cerbero,brion/cerbero,brion/cerbero,centricular/cerbero,justinjoy/cerbero,ford-prefect/cerbero,nirbheek/cerbero,ikonst/cerbero,shoreflyer/cerbero,EricssonResearch/cerbero,lubosz/cerbero,freedesktop-unofficial-mirror/gstreamer__cerbero,flexVDI/cerbero,OptoFidelity/cerbero,ramaxlo/cerbero,AlertMe/cerbero,ramaxlo/cerbero,superdump/cerbero,nzjrs/cerbero,flexVDI/cerbero,shoreflyer/cerbero,freedesktop-unofficial-mirror/gstreamer__cerbero,justinjoy/cerbero,lubosz/cerbero,multipath-rtp/cerbero,AlertMe/cerbero,multipath-rtp/cerbero,atsushieno/cerbero,nzjrs/cerbero,ramaxlo/cerbero,fluendo/cerbero,sdroege/cerbero,ramaxlo/cerbero,freedesktop-unofficial-mirror/gstreamer__sdk__cerbero,GStreamer/cerbero,centricular/cerbero,ford-prefect/cerbero,centricular/cerbero,lubosz/cerbero,sdroege/cerbero,nirbheek/cerbero-old,atsushieno/cerbero,multipath-rtp/cerbero,GStreamer/cerbero,brion/cerbero,ikonst/cerbero,atsushieno/cerbero,OptoFidelity/cerbero,GStreamer/cerbero,superdump/cerbero,AlertMe/cerbero,ikonst/cerbero,multipath-rtp/cerbero,flexVDI/cerbero,ford-prefect/cerbero,freedesktop-unofficial-mirror/gstreamer__sdk__cerbero,jackjansen/cerbero,superdump/cerbero,brion/cerbero,freedesktop-unofficial-mirror/gstreamer__sdk__cerbero,justinjoy/cerbero,GStreamer/cerbero,ikonst/cerbero,nirbheek/cerbero-old,lubosz/cerbero,GStreamer/cerbero,nirbheek/cerbero,EricssonResearch/cerbero