Kernel memory exhaustion via unreleased control handlers

A memory leak in the i.MX CSC/scaler driver in affected Linux kernel versions allows local users to exhaust kernel memory. Each successful device open initializes three controls, but ipu_csc_scaler_release omitted v4l2_ctrl_handler_free, so every close retained the handler allocations. Local low-privileged access to the i.MX media mem2mem device is required, and repeated open-and-close cycles can consume kernel memory until service interruption.