Fix resampling code to deal with case in which output frequency is greater than the input frequency. Probably could stand to be improved, but at least it doesn't cause the emulator to deadlock

#ifndef PPM_H_
#define PPM_H_

void save_ppm(FILE *f, uint32_t *buffer, uint32_t width, uint32_t height, uint32_t pitch);

#endif //PPM_H_