drm/xe: Do not kill VM in PT code on -ENODATA

No need kill on -ENODATA as is this non-fatal error can occur when MMU
notifiers race with prefetches.

Fixes: 09ba0a8f ("drm/xe/svm: Implement prefetch support for SVM ranges")
Cc: stable@vger.kernel.org
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com&gt;>
Link: https://lore.kernel.org/r/20250613231808.752616-1-matthew.brost@intel.com