Bug 284366 PSM needs to handle Smart Cards seamlessly

fix casting on 64bit platforms
patch by ajschult@verizon.net r=rrelyea sr=jst a=asa

security/manager/ssl/src/nsSmartCardMonitor.cpp

@@ -131,7 +131,7 @@ SmartCardThreadList::Add(SmartCardMonitoringThread *thread)
 
 // We really should have a Unity PL Hash function...
 static PR_CALLBACK PLHashNumber
-unity(const void *key) { return (PLHashNumber)key; }
+unity(const void *key) { return PLHashNumber(NS_PTR_TO_INT32(key)); }
 
 SmartCardMonitoringThread::SmartCardMonitoringThread(SECMODModule *module_)
   : mThread(nsnull)