[OS/2][BeOS] Bug 474365: unbreak build in widget/src/*/nsDeviceContextSpec*.cpp following bug 461047, r=weilbacher

widget/src/beos/nsDeviceContextSpecB.cpp

@@ -64,7 +64,7 @@ public:
 
   PRBool    PrintersAreAllocated()       { return mGlobalPrinterList != nsnull; }
   PRInt32   GetNumPrinters()             { return mGlobalNumPrinters; }
-  nsString* GetStringAt(PRInt32 aInx)    { return mGlobalPrinterList->StringAt(aInx); }
+  nsString* GetStringAt(PRInt32 aInx)    { return &mGlobalPrinterList->ElementAt(aInx); }
 
 protected:
   GlobalPrinters() {}

widget/src/os2/nsDeviceContextSpecOS2.cpp

@@ -83,7 +83,7 @@ public:
 
   PRBool    PrintersAreAllocated()       { return mGlobalPrinterList != nsnull; }
   PRInt32   GetNumPrinters()             { return mGlobalNumPrinters; }
-  nsString* GetStringAt(PRInt32 aInx)    { return mGlobalPrinterList->StringAt(aInx); }
+  nsString* GetStringAt(PRInt32 aInx)    { return &mGlobalPrinterList->ElementAt(aInx); }
   void      GetDefaultPrinterName(PRUnichar*& aDefaultPrinterName);
 
 protected: