AGM: remove all aif_obj from aif_pool after close a session

After close a session, removing all aif_obj from the session's
aif_pool in sess_obj. This prevents a potential race condition
which a dev_obj that's added by a previously closed session to
be used in a different use case's new session. This issue can
cause failure in session_apply_aif_device_params for graph set
config when speaker protection is enabled.

Change-Id: I4ed9571c598aa974761a144ecc704dcaf98ab9a3
diff --git a/service/src/session_obj.c b/service/src/session_obj.c
index 1050acb..be3591a 100644
--- a/service/src/session_obj.c
+++ b/service/src/session_obj.c
@@ -1299,6 +1299,8 @@
                 free(aif_obj->tag_config);
                 aif_obj->tag_config = NULL;
             }
+            list_remove(&aif_obj->node);
+            aif_free(aif_obj);
         }
     }
     pthread_mutex_unlock(&hwep_lock);