use inventory_dir for host_vars directory

tasks/save.yml

@@ -1,7 +1,13 @@
 ---
 
 - name: host_vars directory
-  local_action: file path=host_vars/{{inventory_hostname}} state=directory
+  local_action: file
+  args:
+    path: "{{inventory_dir}}/host_vars/{{inventory_hostname}}"
+    state: directory
 
 - name: host_vars file
-  local_action: template src=host_vars.j2 dest=host_vars/{{inventory_hostname}}/ssh_host_key.yml
+  local_action: template
+  args:
+    src: host_vars.j2
+    dest: "{{inventory_dir}}/host_vars/{{inventory_hostname}}/ssh_host_key.yaml"