Fixes compilation with GCC10.

--- a/ifd/ifd.cpp
+++ b/ifd/ifd.cpp
@@ -958,7 +958,7 @@
   else
     l_atrLength=0;
   rj=r->IfdPower(mode, Atr, &l_atrLength);
-  switch (rj) {
+  switch (static_cast<NTSTATUS>(rj)) {
   case STATUS_SUCCESS:
     DEBUGLUN(Lun, DEBUG_MASK_IFD, "Success (ATR: %d bytes)\n", (int)l_atrLength);
     rc=IFD_SUCCESS;