drm/xe: Ensure __must_check for xe_force_wake_get() return

drm/xe: Ensure __must_check for xe_force_wake_get() return

Add __must_check attribute for xe_force_wake_get().

Cc: Badal Nilawar <badal.nilawar@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Reviewed-by: Badal Nilawar <badal.nilawar@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241014075601.2324382-26-himal.prasad.ghimiray@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>