base-files: split user/group addition code into a function

Signed-off-by: John Crispin <john@phrozen.org>

package/base-files/files/lib/functions.sh

@@ -173,11 +173,9 @@ default_prerm() {
 	done
 }
 
-default_postinst() {
+add_group_and_user() {
-	local root="${IPKG_INSTROOT}"
+	local pkgname="$1"
-	local pkgname="$(basename ${1%.*})"
 	local rusers="$(sed -ne 's/^Require-User: *//p' $root/usr/lib/opkg/info/${pkgname}.control 2>/dev/null)"
-	local ret=0
 
 	if [ -n "$rusers" ]; then
 		local tuple oIFS="$IFS"
@@ -208,6 +206,14 @@ default_postinst() {
 			unset uid gid uname gname
 		done
 	fi
+}
+
+default_postinst() {
+	local root="${IPKG_INSTROOT}"
+	local pkgname="$(basename ${1%.*})"
+	local ret=0
+
+	add_group_and_user "${pkgname}"
 
 	if [ -f "$root/usr/lib/opkg/info/${pkgname}.postinst-pkg" ]; then
 		( . "$root/usr/lib/opkg/info/${pkgname}.postinst-pkg" )