Fix a minor issue in test

Author: andishgar

cpp/src/arrow/scalar_test.cc

@@ -582,13 +582,10 @@ template <typename CType>
 bool IsScalarEqual(CType left, CType right, const EqualOptions& options) {
   std::shared_ptr<Scalar> scalar_left;
   std::shared_ptr<Scalar> scalar_right;
-  if constexpr (std::is_floating_point_v<CType>) {
-    scalar_left = CreateScalar<typename CTypeTraits<CType>::ScalarType>(left);
-    scalar_right = CreateScalar<typename CTypeTraits<CType>::ScalarType>(right);
-  } else {
-    scalar_left = CreateScalar<HalfFloatScalar>(left);
-    scalar_right = CreateScalar<HalfFloatScalar>(right);
-  }
+
+  scalar_left = CreateScalar<typename CTypeTraits<CType>::ScalarType>(left);
+  scalar_right = CreateScalar<typename CTypeTraits<CType>::ScalarType>(right);
+
   return scalar_left->Equals(*scalar_right, options);
 }