Remove the saving of the USB_GetNextDescriptorComp() return value in all host demos, since it went unused anyway; replaced with a simple check against the success error code for clarity.
Capitolised the "Descriptor_Search" and "Descriptor_Search_Comp" prefixes of the values in the DSearch_Return_ErrorCodes_t and DSearch_Comp_Return_ErrorCodes_t enums.
Minor documentation improvements.