fix compiler warnings

src/device-types/HASelect.cpp

@@ -174,7 +174,7 @@ bool HASelect::publishState(const int8_t state)
         return false;
     }
 
-    if (state == -1) {
+    if (state < 0) {
         return publishOnDataTopic(AHATOFSTR(HAStateTopic), AHATOFSTR(HAStateNone), true);
     }
 

src/utils/HASerializerArray.cpp

@@ -30,7 +30,7 @@ bool HASerializerArray::add(ItemType item)
 
 const char* HASerializerArray::getItem(const uint8_t index) const
 {
-    if (index < 0 || index >= _itemsNb) {
+    if (index >= _itemsNb) {
         return nullptr;
     }