Adding null check avoid dereferencing prior to init (#2547) (#2548)

Author: timmiesmith

include/oneapi/dpl/internal/dynamic_selection_impl/auto_tune_policy.h

@@ -208,7 +208,10 @@ class auto_tune_policy : public policy_base<auto_tune_policy<ResourceType, Resou
         static_assert(sizeof...(KeyArgs) == sizeof...(Args));
         if constexpr (backend_traits<Backend>::lazy_report_v)
         {
-            this->backend_->lazy_report();
+            if (this->backend_)
+                this->backend_->lazy_report();
+            else
+                throw std::logic_error("selection called before initialization");
         }
         if (state_)
         {

include/oneapi/dpl/internal/dynamic_selection_impl/dynamic_load_policy.h

@@ -125,7 +125,10 @@ class dynamic_load_policy
     {
         if constexpr (backend_traits<Backend>::lazy_report_v)
         {
-            this->backend_->lazy_report();
+            if (this->backend_)
+                this->backend_->lazy_report();
+            else
+                throw std::logic_error("selection called before initialization");
         }
         if (selector_)
         {