remoteexec: fix reclient command in build_packages

To fix failure here: https://ci.chromium.org/ui/p/chromeos/builders/informational/amd64-generic-remoteexec-informational/b8828371006869454385/overview

Change-Id: I47b33046f97b652a8414fe304c1f4501a5e49194
Bug: 1256966
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/3325494
Reviewed-by: Fumitoshi Ukai <ukai@google.com>
Reviewed-by: Alex Klein <saklein@chromium.org>
Tested-by: Joanna Wang <jojwang@chromium.org>
Commit-Queue: Joanna Wang <jojwang@chromium.org>
diff --git a/build_packages b/build_packages
index 7e6d52f..1d5cd21 100755
--- a/build_packages
+++ b/build_packages
@@ -488,8 +488,8 @@
     info "Starting RBE reproxy."
     bootstrap="'${RECLIENT_DIR}/boostrap' --cfg='${REPROXY_CFG}' \
       --re_proxy='${RECLIENT_DIR}/reproxy'"
-    "${boostrap}"
-    trap "'${boostrap}' --shutdown" EXIT
+    ${boostrap}
+    trap "${boostrap} --shutdown" EXIT
   # Support goma on bots. This has to run in subshell, otherwise EXIT trap
   # handler is overwritten.
   elif [[ "${FLAGS_run_goma}" -eq "${FLAGS_TRUE}" ]]; then