Undefined SCARD_ATTR_VENDOR_NAME compile error
The macro usage introduced by http://sourceforge.net/p/rdesktop/code/1724/

On Mac defined here on mac but reader.h is not distributed.
http://smartcardservices.macosforge.org/trac/browser/releases/Apple/OSX-10.8.0/SmartCardServices-55105/src/PCSC/reader.h
#define SCARD_ATTR_VALUE(Class, Tag) ((((ULONG)(Class)) << 16) | ((ULONG)(Tag)))
#define SCARD_CLASS_VENDOR_INFO     1   // Vendor information definitions
....
#define SCARD_ATTR_VENDOR_NAME SCARD_ATTR_VALUE(SCARD_CLASS_VENDOR_INFO, 0x0100)
it should be 1<<16 | 0x100  (65792)
(same as defined in winsmcrd.h for Windows platform)

However I don't want to fix it blindly and I suspect few users use rdesktop with smart card so just disable it.