resolving issue which was overwriting `/usr/local/bin`, `/usr/local/share/man/man1`, `/usr/local/sbin` and `/usr/local/share/man/man8`, for sure there are better ways, but I was not sure why cp has been used instead of install

gpio/Makefile

@@ -207,13 +207,13 @@ tags:	$(SRC)
 .PHONY:	install
 install: gpio
 	$Q echo "[Install]"
-	$Q cp gpio		$(DESTDIR)$(PREFIX)/bin
+	$Q cp gpio		$(DESTDIR)$(PREFIX)/bin/
 ifneq ($(WIRINGPI_SUID),0)
 	$Q chown root.root	$(DESTDIR)$(PREFIX)/bin/gpio
 	$Q chmod 4755		$(DESTDIR)$(PREFIX)/bin/gpio
 endif
 	$Q mkdir -p		$(DESTDIR)$(PREFIX)/share/man/man1
-	$Q cp gpio.1		$(DESTDIR)$(PREFIX)/share/man/man1
+	$Q cp gpio.1		$(DESTDIR)$(PREFIX)/share/man/man1/
 
 .PHONY:	install-deb
 install-deb:	gpio

wiringPiD/Makefile

@@ -69,11 +69,11 @@ tags:	$(SRC)
 install: wiringpid
 	$Q echo "[Install]"
 	$Q mkdir -p		$(DESTDIR)$(PREFIX)/sbin
-	$Q cp wiringpid		$(DESTDIR)$(PREFIX)/sbin
+	$Q cp wiringpid		$(DESTDIR)$(PREFIX)/sbin/
 	$Q chown root.root	$(DESTDIR)$(PREFIX)/sbin/wiringpid
 
 #	$Q mkdir -p		$(DESTDIR)$(PREFIX)/man/man8
-#	$Q cp gpio.1		$(DESTDIR)$(PREFIX)/man/man8
+#	$Q cp gpio.1		$(DESTDIR)$(PREFIX)/man/man8/
 
 .PHONY:	install-deb
 install-deb:	gpio