fix freebsd

Author: gnzlbg

ci/run.sh

@@ -54,7 +54,8 @@ if [ "$QEMU" != "" ]; then
     --test main
   rm "${CARGO_TARGET_DIR}/${TARGET}"/debug/main-*.d
   cp "${CARGO_TARGET_DIR}/${TARGET}"/debug/main-* "${tmpdir}"/mount/libc-test
-  echo "exec ${1}/libc-test" > "${tmpdir}/mount/run.sh"
+  # shellcheck disable=SC2016
+  echo 'exec $1/libc-test' > "${tmpdir}/mount/run.sh"
 
   du -sh "${tmpdir}/mount"
   genext2fs \