libostree: Document and annotate some methods to quash g-ir-scanner warnings

Since warnings are bad.  Introspection is good.

src/libostree/ostree-deployment.c

@@ -71,12 +71,24 @@ ostree_deployment_get_bootserial (OstreeDeployment *self)
   return self->bootserial;
 }
 
+/**
+ * ostree_deployment_get_bootconfig:
+ * @self: Deployment
+ *
+ * Returns: (transfer none): Boot configuration
+ */
 OstreeBootconfigParser *
 ostree_deployment_get_bootconfig (OstreeDeployment *self)
 {
   return self->bootconfig;
 }
 
+/**
+ * ostree_deployment_get_origin:
+ * @self: Deployment
+ *
+ * Returns: (transfer none): Origin
+ */
 GKeyFile *
 ostree_deployment_get_origin (OstreeDeployment *self)
 {
@@ -117,6 +129,12 @@ ostree_deployment_set_origin (OstreeDeployment *self, GKeyFile *origin)
     self->origin = g_key_file_ref (origin);
 }
 
+/**
+ * ostree_deployment_clone:
+ * @self: Deployment
+ *
+ * Returns: (transfer full): New deep copy of @self
+ */
 OstreeDeployment *
 ostree_deployment_clone (OstreeDeployment *self)
 {

src/libostree/ostree-sysroot.c

@@ -1057,6 +1057,8 @@ _ostree_sysroot_kernel_arg_string_serialize (OstreeOrderedHash *ohash)
  *
  * Find the deployment to use as a configuration merge source; this is
  * the first one in the current deployment list which matches osname.
+ *
+ * Returns: (transfer full): Configuration merge deployment
  */
 OstreeDeployment *
 ostree_sysroot_get_merge_deployment (OstreeSysroot     *self,