PR review fix:

- bind behaviour to not change existing port or address if the requested ones are 0
- removed temporary array setting to zero

features/cellular/framework/AT/ATHandler.cpp

@@ -32,7 +32,7 @@ using namespace events;
 #include "CellularLog.h"
 
 // this is intentionally TRACE_LEVEL_INFO
-#if MBED_TRACE_MAX_LEVEL <= TRACE_LEVEL_INFO
+#if MBED_TRACE_MAX_LEVEL >= TRACE_LEVEL_INFO
 #define at_debug(format, ...) do { if (_debug_on) debug(format, ## __VA_ARGS__); } while (0)
 #else
 #define at_debug(...)

features/cellular/framework/AT/AT_CellularStack.cpp

@@ -169,10 +169,13 @@ nsapi_error_t AT_CellularStack::socket_bind(nsapi_socket_t handle, const SocketA
     if (!socket) {
         return NSAPI_ERROR_DEVICE_ERROR;
     }
-    socket->localAddress = addr;
 
-    if (socket->localAddress.get_port() == 0) {
-        socket->localAddress.set_port(get_dynamic_ip_port());
+    if (addr) {
+        socket->localAddress.set_addr(addr.get_addr());
+    }
+
+    if (addr.get_port()) {
+        socket->localAddress.set_port(addr.get_port());
     }
 
     _at.lock();

features/cellular/framework/targets/QUECTEL/BC95/QUECTEL_BC95_CellularStack.cpp

@@ -167,7 +167,7 @@ nsapi_size_or_error_t QUECTEL_BC95_CellularStack::socket_recvfrom_impl(CellularS
     nsapi_size_or_error_t recv_len=0;
     int port;
     char ip_address[NSAPI_IP_SIZE];
-    char hexstr[BC95_MAX_PACKET_SIZE*2 + 1] = {0};
+    char hexstr[BC95_MAX_PACKET_SIZE*2 + 1];
 
     _at.cmd_start("AT+NSORF=");
     _at.write_int(socket->id);