hw/rx/rx-gdbsim: Remove unnecessary uses of &first_cpu

rx_gdbsim_init() has access to the single CPU via:

  RxGdbSimMachineState {
    RX62NState {
      RXCPU cpu;
      ...
    } mcu;
  } s;

Directly use that instead of the &first_cpu global.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250110180442.82687-1-philmd@linaro.org>
1 file changed