drm/xe: Remove unrequired NULL checks in xe_sync_entry_cleanup

dma_fence_put() and dma_fence_chain_free() can handle NULL input,
there is no need for NULL check by caller.

Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240820090230.3258128-2-himal.prasad.ghimiray@intel.com


Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>