setPyVirTypedParameter: free whole return variable on error
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 <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

libvirt/libvirt-python,libvirt/libvirt-python,libvirt/libvirt-python