drm/xe/migrate: Fix an error path

drm/xe/migrate: Fix an error path

The exhaustive eviction accidently changed an error path goto to
a return. Fix this.

Fixes: 59eabff2a352 ("drm/xe: Convert xe_bo_create_pin_map() for exhaustive eviction")
Cc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Francois Dugast <francois.dugast@intel.com>
Link: https://lore.kernel.org/r/20250910160939.103473-1-thomas.hellstrom@linux.intel.com
(cherry picked from commit 381f1ed15159c4b3f00dd37cc70924dedebeb111)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>