review updates

Co-authored-by: Yu-Hsiang Tsai <yhmtsai@gmail.com>

Author: upsj

include/ginkgo/core/stop/iteration.hpp

@@ -32,10 +32,10 @@ class Iteration : public EnablePolymorphicObject<Iteration, Criterion> {
          */
         size_type max_iters{0};
 
-        auto with_max_iters(size_type value)->parameters_type&
+        parameters_type& with_max_iters(size_type value)
         {
             this->max_iters = value;
-            return *(this->self());
+            return *this;
         }
     };
     GKO_ENABLE_CRITERION_FACTORY(Iteration, parameters, Factory);

include/ginkgo/core/stop/residual_norm.hpp

@@ -123,8 +123,7 @@ class ResidualNorm : public ResidualNormBase<ValueType> {
         remove_complex<ValueType> reduction_factor{
             5 * std ::numeric_limits<remove_complex<ValueType>>::epsilon()};
 
-        auto with_reduction_factor(remove_complex<ValueType> value)
-            ->parameters_type&
+        parameters_type& with_reduction_factor(remove_complex<ValueType> value)
         {
             this->reduction_factor = value;
             return *this;
@@ -186,8 +185,7 @@ class ImplicitResidualNorm : public ResidualNormBase<ValueType> {
         remove_complex<ValueType> reduction_factor{
             5 * std ::numeric_limits<remove_complex<ValueType>>::epsilon()};
 
-        auto with_reduction_factor(remove_complex<ValueType> value)
-            ->parameters_type&
+        parameters_type& with_reduction_factor(remove_complex<ValueType> value)
         {
             this->reduction_factor = value;
             return *this;
@@ -268,8 +266,7 @@ class GKO_DEPRECATED(
         remove_complex<ValueType> reduction_factor{
             5 * std ::numeric_limits<remove_complex<ValueType>>::epsilon()};
 
-        auto with_reduction_factor(remove_complex<ValueType> value)
-            ->parameters_type&
+        parameters_type& with_reduction_factor(remove_complex<ValueType> value)
         {
             this->reduction_factor = value;
             return *this;
@@ -330,8 +327,9 @@ class GKO_DEPRECATED(
          */
         remove_complex<ValueType> tolerance{
             5 * std ::numeric_limits<remove_complex<ValueType>>::epsilon()};
-        template <typename... Args>
-        auto with_tolerance(remove_complex<ValueType> value)->parameters_type&
+
+
+        parameters_type& with_tolerance(remove_complex<ValueType> value)
         {
             this->tolerance = value;
             return *this;
@@ -390,7 +388,7 @@ class GKO_DEPRECATED(
         remove_complex<ValueType> tolerance{
             5 * std ::numeric_limits<remove_complex<ValueType>>::epsilon()};
 
-        auto with_tolerance(remove_complex<ValueType> value)->parameters_type&
+        parameters_type& with_tolerance(remove_complex<ValueType> value)
         {
             this->tolerance = value;
             return *this;