drm/xe: Remove debug message from migrate_clear()

This messages is printed a lot and from my understanding it do not
bring any value, so here dropping it.

Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240405153849.44906-1-jose.souza@intel.com