[WiFiScan] Use nullptr instead of 0

As suggested by @me-no-dev

Author: TD-er

libraries/WiFi/src/WiFiScan.cpp

@@ -48,7 +48,7 @@ uint32_t WiFiScanClass::_scanTimeout = 60000;
 uint16_t WiFiScanClass::_scanCount = 0;
 uint32_t WiFiScanClass::_scanActiveMinTime = 100;
 
-void *WiFiScanClass::_scanResult = 0;
+void *WiFiScanClass::_scanResult = nullptr;
 
 void WiFiScanClass::setScanTimeout(uint32_t ms) {
   WiFiScanClass::_scanTimeout = ms;
@@ -119,7 +119,7 @@ void WiFiScanClass::_scanDone() {
   esp_wifi_scan_get_ap_num(&(WiFiScanClass::_scanCount));
   if (WiFiScanClass::_scanResult) {
     delete[] reinterpret_cast<wifi_ap_record_t *>(WiFiScanClass::_scanResult);
-    WiFiScanClass::_scanResult = 0;
+    WiFiScanClass::_scanResult = nullptr;
   }
 
   if (WiFiScanClass::_scanCount) {
@@ -128,7 +128,7 @@ void WiFiScanClass::_scanDone() {
       WiFiScanClass::_scanCount = 0;
     } else if (esp_wifi_scan_get_ap_records(&(WiFiScanClass::_scanCount), (wifi_ap_record_t *)_scanResult) != ESP_OK) {
       delete[] reinterpret_cast<wifi_ap_record_t *>(WiFiScanClass::_scanResult);
-      WiFiScanClass::_scanResult = 0;
+      WiFiScanClass::_scanResult = nullptr;
       WiFiScanClass::_scanCount = 0;
     }
   }
@@ -181,7 +181,7 @@ void WiFiScanClass::scanDelete() {
   WiFiGenericClass::clearStatusBits(WIFI_SCAN_DONE_BIT);
   if (WiFiScanClass::_scanResult) {
     delete[] reinterpret_cast<wifi_ap_record_t *>(WiFiScanClass::_scanResult);
-    WiFiScanClass::_scanResult = 0;
+    WiFiScanClass::_scanResult = nullptr;
     WiFiScanClass::_scanCount = 0;
   }
 }