Eliminated two compilation warnings.

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@648 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/win/rfb_win32/SFileTransferWin32.cxx b/win/rfb_win32/SFileTransferWin32.cxx
index 5aea412..0894d73 100644
--- a/win/rfb_win32/SFileTransferWin32.cxx
+++ b/win/rfb_win32/SFileTransferWin32.cxx
@@ -118,8 +118,8 @@
 
   if (dw64DirSize & 0xFFFF000000000000) return false;
 
-  *pHighSize16 = ((dw64DirSize & 0x0000FFFF00000000) >> 32);
-  *pLowSize32 = (dw64DirSize & 0x00000000FFFFFFFF);
+  *pHighSize16 = (unsigned short)((dw64DirSize >> 32) & 0xFFFF);
+  *pLowSize32 = (unsigned int)(dw64DirSize & 0xFFFFFFFF);
 
   return true;
 }