DRAFT *.bbclass: Drop assignments of S (generated recipes set it correctly)

classes/ament-python.bbclass

@@ -1,7 +1,5 @@
 # Copyright (c) 2018-2019 LG Electronics, Inc.
 
-S = "${WORKDIR}/git/${ROS_BPN}"
-
 inherit setuptools3
 
 do_install_append() {

classes/ament.bbclass

@@ -18,8 +18,6 @@ DEPENDS_append = " \
     ament-cmake-test-native \
 "
 
-S = "${WORKDIR}/git/${ROS_BPN}"
-
 EXTRA_OECMAKE_append = " -DBUILD_TESTING=OFF -DPYTHON_SOABI=cpython-35m-${TUNE_ARCH}-${TARGET_OS}${ARMPKGSFX_EABI}"
 export AMENT_PREFIX_PATH="${STAGING_DIR_HOST}${prefix};${STAGING_DIR_NATIVE}${prefix}"