Don't override SYSROOT for our usage
Don't override SYSROOT for our usage

Otherwise it will always be set, and for newer ndk-build versions that
don't set it automatically it will contain the sysroot for the first
target architecture if building for multiple.

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