This patch attempts to update the code to load CMYK PSD files to fully using the babl library. Currently, gimp_color_transform_process_pixels () is used if a profile is attached, and babl_process () is called if there's no profile.
By using babl_format_with_space () for images with CMYK profiles instead, all CMYK PSD files can be processed through babl_process (). This incidentally simplifies the code and conditional logic as well.