usb: cdc_acm: Fix composite build

Fixes bug below:
subsys/usb/class/cdc_acm.c:554:15: error: ‘dev_data’ undeclared (first
use in this function) k_work_init(&dev_data->cb_work,
cdc_acm_irq_callback_work_handler); ^~~~~~~~

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
1 file changed