eliminate calls to deprecated Use::init() interface

llvm-svn: 51570

llvm/lib/Bitcode/Reader/BitcodeReader.h

@@ -89,7 +89,7 @@ private:
       resize(Idx * 2 + 1);
     }
     assert(getOperand(Idx) == 0 && "Cannot init an already init'd Use!");
-    OperandList[Idx].init(V, this);
+    OperandList[Idx] = V;
   }
 };