build: use cp -R as -cp -r is actually -RL

And this is being disliked by a dangling python3 -> python3.6 link.

build/common.sh

@@ -429,7 +429,7 @@ setup_copy()
 	# in case we want to clobber HEAD
 	rm -rf ${1}${2}
 	mkdir -p $(dirname ${1}${2})
-	cp -r ${2} ${1}${2}
+	cp -R ${2} ${1}${2}
 }
 
 setup_xbase()

build/ports.sh

@@ -105,7 +105,7 @@ trap : 2
 ${ENV_FILTER} chroot ${STAGEDIR} /bin/sh -s << EOF || true
 # create a caching mirror for all temporary package dependencies
 mkdir -p ${PACKAGESDIR}-cache
-cp -r ${PACKAGESDIR}/All ${PACKAGESDIR}-cache/All
+cp -R ${PACKAGESDIR}/All ${PACKAGESDIR}-cache/All
 
 echo "${PORTS_LIST}" | while read PORT_ORIGIN; do
 	FLAVOR=\${PORT_ORIGIN##*@}

build/skim.sh

@@ -190,7 +190,7 @@ if [ -n "${UNUSED}" ]; then
 			echo ">>> Refreshing ${PORT}"
 
 			rm -fr ${PORTSDIR}/${PORT}
-			cp -r ${PORTSREFDIR}/${PORT} ${PORTSDIR}/${PORT}
+			cp -R ${PORTSREFDIR}/${PORT} ${PORTSDIR}/${PORT}
 		done
 	done
 

build/vm.sh

@@ -68,7 +68,7 @@ mount /dev/${DEV} ${STAGEDIR}/mnt
 setup_base ${STAGEDIR}/mnt
 
 # need these again later
-cp -r ${STAGEDIR}/mnt/boot ${STAGEDIR}
+cp -R ${STAGEDIR}/mnt/boot ${STAGEDIR}
 
 setup_kernel ${STAGEDIR}/mnt
 setup_packages ${STAGEDIR}/mnt