kern: avoid constexpr init for many objects (avoids unnecessary memory clear) (#1668)

libraries/libmesosphere/include/mesosphere/kern_k_light_session.hpp

@@ -46,11 +46,7 @@ namespace ams::kern {
             KProcess *m_process;
             bool m_initialized;
         public:
-            constexpr KLightSession()
-                : m_server(), m_client(), m_state(State::Invalid), m_port(), m_name(), m_process(), m_initialized()
-            {
-                /* ... */
-            }
+            explicit KLightSession() : m_state(State::Invalid), m_process(), m_initialized() { /* ... */ }
 
             void Initialize(KClientPort *client_port, uintptr_t name);
             virtual void Finalize() override;