Fixes the following warning: ``` [...]/pico-sdk/src/host/hardware_divider/include/hardware/divider.h:81:26: warning: operand of ?: changes signedness from 'int' to 'uint32_t' {aka 'unsigned int'} due to unsignedness of other operand [-Wsign-compare] return b ? (a / b) : -1; ^~ ```