Cinder: create target directory for targetcli-fb package

While installing 'targetcli-fb' on bionic, a dependent package
'python-rtslib-fb' requires (but doesn't create) /etc/target
and fails[1] when this directory not found.
This patch creates the required directory.

[1] http://logs.openstack.org/26/641926/1/check/cinder-tempest-dsvm-lvm-lio-barbican/8f95df1/logs/devstacklog.txt.gz#_2019-03-13_03_36_44_623

Related-bug: #1819819
Change-Id: I7efefead873037da4aaacbdc6284458bdaad0f6b
diff --git a/lib/cinder b/lib/cinder
index 48f3e45..047b25b 100644
--- a/lib/cinder
+++ b/lib/cinder
@@ -435,6 +435,9 @@
         install_package tgt
     elif [[ "$CINDER_ISCSI_HELPER" == "lioadm" ]]; then
         if [[ ${DISTRO} == "bionic" ]]; then
+            # TODO(frickler): Workaround for https://launchpad.net/bugs/1819819
+            sudo mkdir -p /etc/target
+
             install_package targetcli-fb
         else
             install_package targetcli