unix: always create install/lib/pythonX.Y/lib-dynload/.empty file

In some configurations the directory exists but is empty. We want
there to always be a file to ensure the directory is created and
Python doesn't complain on startup.

Author: indygreg

cpython-unix/build-cpython.sh

@@ -840,10 +840,8 @@ find ${ROOT}/out/python/install -type d -name __pycache__ -print0 | xargs -0 rm
 
 # Ensure lib-dynload exists, or Python complains on startup.
 LIB_DYNLOAD=${ROOT}/out/python/install/lib/python${PYTHON_MAJMIN_VERSION}/lib-dynload
-if [ ! -d ${LIB_DYNLOAD} ]; then
-  mkdir -p ${LIB_DYNLOAD}
-  touch ${LIB_DYNLOAD}/.empty
-fi
+mkdir -p "${LIB_DYNLOAD}"
+touch "${LIB_DYNLOAD}/.empty"
 
 # Symlink libpython so we don't have 2 copies.
 if [ -n "${PYTHON_BINARY_SUFFIX}" ]; then