SelectionDAG: Silence unused variable warning on release builds

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191604 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index e78caba..26d71cc 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -3714,6 +3714,7 @@
 
     bool Legalized = LegalizeSetCCCondCode(getSetCCResultType(
         Tmp2.getValueType()), Tmp2, Tmp3, Tmp4, dl);
+    (void)Legalized;
     assert(Legalized && "Can't legalize BR_CC with legal condition!");
 
     // If we exapanded the SETCC by swapping LHS and RHS, create a new BR_CC