[HAL] Ensure us_ticker and lp_ticker queue are correctly initialized.

Author: pan-

hal/mbed_lp_ticker_api.c

@@ -17,7 +17,7 @@
 
 #if DEVICE_LOWPOWERTIMER
 
-static ticker_event_queue_t events;
+static ticker_event_queue_t events = { 0 };
 
 static const ticker_interface_t lp_interface = {
     .init = lp_ticker_init,

hal/mbed_us_ticker_api.c

@@ -15,7 +15,7 @@
  */
 #include "hal/us_ticker_api.h"
 
-static ticker_event_queue_t events;
+static ticker_event_queue_t events = { 0 };
 
 static const ticker_interface_t us_interface = {
     .init = us_ticker_init,
@@ -27,7 +27,7 @@ static const ticker_interface_t us_interface = {
 
 static const ticker_data_t us_data = {
     .interface = &us_interface,
-    .queue = &events,
+    .queue = &events
 };
 
 const ticker_data_t* get_us_ticker_data(void)