Fix a couple cases where iterating all entities wasn't done correctly

Author: Vauff

src/entwatch.cpp

@@ -735,7 +735,7 @@ void EWItemInstance::FindExistingHandlers()
 			continue;
 
 		CBaseEntity* pTarget = nullptr;
-		while ((pTarget = UTIL_FindEntityByName(pTarget, "*")))
+		while ((pTarget = UTIL_FindEntityByClassname(pTarget, "*")))
 		{
 			if (!V_strcmp(pTarget->m_sUniqueHammerID().Get(), handler->szHammerid.c_str()))
 			{

src/mapmigrations.cpp

@@ -104,7 +104,7 @@ void CMapMigrations::UpdateMapUpdateTime(time_t timeMapUpdated)
 	CBaseEntity* pTarget = nullptr;
 
 	// May be called late, so also check any existing entities first
-	while ((pTarget = UTIL_FindEntityByName(pTarget, "*")))
+	while ((pTarget = UTIL_FindEntityByClassname(pTarget, "*")))
 		RunMigrations(pTarget);
 }