Running ARCH=all build.sh (which is called by make build-all) had an error in its sh test, which in turn would cause it to use the wrong Dockerfile and builds would fail. This fixes it.
The cross-builder image was tagged by the target arch rather than the builder arch, which made no sense and led to a proliferation of tags
build-all did not build s390x, even though that build actually does work, and the image is just a scratch image without qemu emulation, so we can build it, and make image does build it. This ensures it does.
Description
Fixes several things:
ARCH=all build.sh(which is called bymake build-all) had an error in itsshtest, which in turn would cause it to use the wrongDockerfileand builds would fail. This fixes it.build-alldid not builds390x, even though that build actually does work, and the image is just ascratchimage withoutqemuemulation, so we can build it, andmake imagedoes build it. This ensures it does.