docker: fix recent regression in RPATH

fixes #3242

This error was not caught by build scripts, obviously.

Signed-off-by: Øyvind Harboe <[email protected]>

Author: oharboe

build_openroad.sh

@@ -211,9 +211,10 @@ fi
 
 # Only add install prefix variables after parsing arguments.
 YOSYS_ARGS+=" PREFIX=${INSTALL_PATH}/yosys"
-OPENROAD_APP_ARGS+=" -D CMAKE_INSTALL_PREFIX=${INSTALL_PATH}/OpenROAD "
+OPENROAD_APP_ARGS+=" -D CMAKE_INSTALL_PREFIX=${INSTALL_PATH}/OpenROAD"
 if [ -n "$CMAKE_INSTALL_RPATH" ]; then
-        OPENROAD_APP_ARGS+="-D CMAKE_INSTALL_RPATH=${CMAKE_INSTALL_RPATH}"
+        OPENROAD_APP_ARGS+=" -D CMAKE_INSTALL_RPATH=${CMAKE_INSTALL_RPATH}"
+        OPENROAD_APP_ARGS+=" -D CMAKE_INSTALL_RPATH_USE_LINK_PATH=TRUE"
 fi
 LSORACLE_ARGS+=" \
 -D YOSYS_SHARE_DIR=${INSTALL_PATH}/yosys/share/yosys \