Remove undefined PRIVATE_* variable

This variable isn't defined for $(jack_lib), and isn't needed, since we
haven't created our intermediate directory at this point.

Test: Run in different configurations (no options, dist tests), make
      sure this command line doesn't change.
Change-Id: Ie863e1e632a9b6eb343b3f411f6c6cc548fa2a2c

build/build_android_stubs.mk

@@ -75,7 +75,6 @@ $(jack_lib) : $(stub_timestamp) $(framework_res_package) $(JACK_DEFAULT_ARGS) $(
 	rm -rf $(PRIVATE_INTERMEDIATES_DIR)/jack-rsc.tmp
 	$(hide) if [ ! -f $(PRIVATE_FRAMEWORK_RES_PACKAGE) ]; then \
 		echo Missing file $(PRIVATE_FRAMEWORK_RES_PACKAGE); \
-		rm -rf $(PRIVATE_CLASS_INTERMEDIATES_DIR); \
 		exit 1; \
 	fi;
 	mkdir -p $(PRIVATE_INTERMEDIATES_DIR)/jack-rsc.tmp