drm/i915: remove i915_drm_client::id

i915_drm_client::id is not used since commit e894b724 (drm/i915:
Use the fdinfo helper). Drop it.

Found by https://github.com/jirislaby/clang-struct.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240216065326.6910-10-jirislaby@kernel.org

drivers/gpu/drm/i915/i915_drm_client.h

@@ -24,8 +24,6 @@ struct drm_printer;
 struct i915_drm_client {
 	struct kref kref;
 
-	unsigned int id;
-
 	spinlock_t ctx_lock; /* For add/remove from ctx_list. */
 	struct list_head ctx_list; /* List of contexts belonging to client. */