setPyVirTypedParameter: free whole return variable on error

The @ret value is built in a loop. However, if in one iteration
there's an error, we should free all the fields built so far. For
instance, if there's an error and the previous item was
type of VIR_TYPED_PARAM_STRING we definitely must free it.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

libvirt-override.c

@@ -259,7 +259,7 @@ setPyVirTypedParameter(PyObject *info,
     return ret;
 
 cleanup:
-    VIR_FREE(ret);
+    virTypedParamsFree(ret, size);
     return NULL;
 }