Cleared warnings on platformio for Arduino Uno

[ciband]

Cleared warnings on platformio for Arduino Uno

.platformio\packages\framework-arduinoavr\libraries\WiFi\src\utility\wifi_drv.cpp: In static member function 'static uint8_t WiFiDrv::getEncTypeNetowrks(uint8_t)':
C:\Users\chris.platformio\packages\framework-arduinoavr\libraries\WiFi\src\utility\wifi_drv.cpp:451:10: warning: converting to non-pointer type 'uint8_t {aka unsigned char}' from NULL [-Wconversion-null]
return NULL;
^
.....platformio\packages\framework-arduinoavr\libraries\WiFi\src\utility\wifi_drv.cpp: In static member function 'static int32_t WiFiDrv::getRSSINetoworks(uint8_t)':
.....platformio\packages\framework-arduinoavr\libraries\WiFi\src\utility\wifi_drv.cpp:476:10: warning: converting to non-pointer type 'int32_t {aka long int}' from NULL [-Wconversion-null]
return NULL;
^

....platformio\packages\framework-arduinoavr\libraries\WiFi\src\utility\spi_drv.cpp:22:0:
C:\Users\chris.platformio\packages\framework-arduinoavr\libraries\WiFi\src/utility/spi_drv.h:41:13: warning: 'initialized' defined but not used [-Wunused-variable]
static bool initialized = false;
^

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[econeale]

How does removing the initialized variable impact the WAIT_FOR_SLAVE_SELECT macro? My solution was to add a diagnostic pragma to that line since I don't understand what the macro is doing: https://github.com/arduino-libraries/WiFi/pull/32