makefile_engine: Revert hrev52738

Reverts hrev52738, as discussed with waddlesplash on IRC.
Re-opens #11419 "makefile_engine's install function fails on paths with blanks"

Turns out this change results in escaped filenames, e.g. "Open Origin Package"
becomes "Open\ Origin\ Package", see
https://github.com/haikuports/haikuports/pull/3580

data/develop/makefile-engine

@@ -366,7 +366,7 @@ ifeq ($(INSTALL_DIR), )
 	@echo "No install directory specified for \"$(NAME)\" (INSTALL_DIR is empty)" >&2
 else
 	mkdir -p "$(INSTALL_DIR)"
-	cp $(TARGET) "$(INSTALL_DIR)/$(NAME)"
+	cp $(TARGET) $(INSTALL_DIR)/$(NAME)
 endif
 
 # Set the catalog installation directory if it isn't already.