contrib: fix regex installation

If regex was the first package installed it would create include
and lib files, instead of include/regex.h and lib/libregex.a

contrib/src/regex/rules.mak

@@ -19,5 +19,7 @@ regex: regex-$(REGEX_VERSION).tar.gz .sum-regex
 .regex: regex
 	cd $< && $(HOSTVARS) ./configure $(HOSTCONF)
 	cd $< && $(MAKE) subirs=
-	cd $< && $(AR) rcvu libregex.a regex.o && $(RANLIB) libregex.a && cp -v regex.h $(PREFIX)/include && cp -v libregex.a $(PREFIX)/lib
+	cd $< && $(AR) rcvu libregex.a regex.o && $(RANLIB) libregex.a
+	mkdir -p $(PREFIX)/include/ && cp $</regex.h $(PREFIX)/include/
+	mkdir -p $(PREFIX)/lib/ && cp $</libregex.a $(PREFIX)/lib/
 	touch $@