Fix install target in Makefile

Makefile

@@ -47,7 +47,7 @@ obj lib:
 	@mkdir $@
 
 install:
-	install lib/$(DT_SHLIB) $(PREFIX)/lib
+	install -D lib/$(DT_SHLIB) $(PREFIX)/lib
 	cd $(PREFIX)/lib; ln -sf $(DT_SHLIB) $(DT_SONAME);ln -sf $(DT_SONAME) $(SHLIB)
 	install -m 644 src/$(TARGET_USER).h $(PREFIX)/include