docs: Use sudo to remove old rootfs in dev guide
You cannot remove an existing rootfs directory without being `root`,
so use `sudo(8)` in the developer guide.
@@ -137,7 +137,7 @@ $ go get -d -u github.com/kata-containers/osbuilder
### Create a local rootfs
```
$ export ROOTFS_DIR=${GOPATH}/src/github.com/kata-containers/osbuilder/rootfs-builder/rootfs
-$ rm -rf ${ROOTFS_DIR}
+$ sudo rm -rf ${ROOTFS_DIR}
$ cd $GOPATH/src/github.com/kata-containers/osbuilder/rootfs-builder
$ script -fec 'sudo -E GOPATH=$GOPATH USE_DOCKER=true ./rootfs.sh ${distro}'
```
@@ -192,7 +192,7 @@ $ (cd /usr/share/kata-containers && sudo ln -sf "$image" kata-containers.img)
### Create a local rootfs for initrd image
```
$ export ROOTFS_DIR="${GOPATH}/src/github.com/kata-containers/osbuilder/rootfs-builder/rootfs"
-$ rm -rf ${ROOTFS_DIR}
+$ sudo rm -rf ${ROOTFS_DIR}
$ cd $GOPATH/src/github.com/kata-containers/osbuilder/rootfs-builder
$ script -fec 'sudo -E GOPATH=$GOPATH AGENT_INIT=yes USE_DOCKER=true ./rootfs.sh ${distro}'
```
