binder: fix kernel-doc warning of 'file' member

The 'struct file' member in 'binder_task_work_cb' definition was renamed
to 'file' between patch versions but its kernel-doc reference kept the
old name 'fd'. Update the naming to fix the W=1 build warning.

Cc: Todd Kjos <tkjos@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501031535.erbln3A2-lkp@intel.com/
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Acked-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/20250106192608.1107362-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/android/binder.c

@@ -1971,7 +1971,7 @@ static bool binder_validate_fixup(struct binder_proc *proc,
  * struct binder_task_work_cb - for deferred close
  *
  * @twork:                callback_head for task work
- * @fd:                   fd to close
+ * @file:                 file to close
  *
  * Structure to pass task work to be handled after
  * returning from binder_ioctl() via task_work_add().