drm/xe/configfs: Drop redundant init() error message

drm/xe/configfs: Drop redundant init() error message

There is no need to print separate error message since we will
also print one in xe_init(). Also drop temporary variable, which
was likely just taken from the example code.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250731193339.179829-5-michal.wajdeczko@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>