ADC injected multi channel example for F103RB not working

[ziteh]

https://github.com/ziteh/stm32-examples/tree/main/libopencm3/adc_multi_channel_injected

stm32-examples/libopencm3/adc_multi_channel_injected/src/main.h

Line 26 in de2106a

#error "Not working, need to fix." /* TODO. */