fix unionfs_dir

git-svn-id: http://trac.vinelinux.org/repos/projects/vbootstrap/trunk@2766 ec354946-7b23-47d6-9f5a-488ba84defc7

vbuilder.sh.in

@@ -465,7 +465,7 @@ mount-chroot-mount(){
 	unionfs_dir)
 	    if [ $with_unionfs -eq 1 ]; then
 		[ -d ${UNIONFS_ROOT} ] || mkdir -p ${UNIONFS_ROOT}
-		[ -z "$(mount | grep ${BUILD_ROOT})" ] && \
+		[ -z "$(mount | grep ${UNIONFS_ROOT})" ] && \
 		    mount -t unionfs -o dirs=${UNIONFS_ROOT}=rw:${BUILD_ROOT}=ro unionfs ${BUILD_ROOT}
 		unionctl ${BUILD_ROOT} --list
 	    fi