minor fix: quote path from which

Author: c-x-berger

cross-build.sh

@@ -6,7 +6,7 @@ for last in "$@"; do :; done
 
 docker_qemu="docker/qemu-arm-static"
 rm -f ${docker_qemu}
-cp $(which qemu-arm-static) ${docker_qemu}
+cp "$(which qemu-arm-static)" ${docker_qemu}
 docker build -t rusty-engine:latest docker/
 rm ${docker_qemu}