python: Initialize new_params in virDomainSetSchedulerParameters
python: Initialize new_params in virDomainSetSchedulerParameters

The new_params variable must be initialized in case the
virDomainGetSchedulerParameters call fails and we hit the cleanup
section before actually allocating the new parameters.

Signed-off-by: Federico Simoncelli <d5e4d7da1feaf2c79fa6885a7451e8a6a68321fc@redhat.com>

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