[CI] Simplify PKG_CONFIG_PATH for cargo_update.sh
With recent changes, the only thing needed in `PKG_CONFIG_PATH` is the
ZeroMQ entry.
(As it was, this was failing because `PKG_CONFIG_PATH` was unset in
the environment. Since we don't need to concatenate anything, we'll
just set the value directly and move on.)
@@ -18,7 +18,7 @@ install_hub
echo "--- :habicat: Installing and configuring build dependencies"
hab pkg install core/zeromq
-PKG_CONFIG_PATH="$PKG_CONFIG_PATH:$(< "$(hab pkg path core/zeromq)"/PKG_CONFIG_PATH)"
+PKG_CONFIG_PATH="$(< "$(hab pkg path core/zeromq)"/PKG_CONFIG_PATH)"
export PKG_CONFIG_PATH
# The library detection for the zeromq crate needs this additional hint.
