Cellular: review fix removed magic numbers from unit tests.

Author: Teppo Järvelin

features/cellular/UNITTESTS/at/at_cellulardevice/test_at_cellulardevice.cpp

@@ -122,7 +122,7 @@ void Test_AT_CellularDevice::test_AT_CellularDevice_close_network()
     CHECK(ATHandler_stub::ref_count == 1);
 
     dev.close_network();
-    CHECK(ATHandler_stub::ref_count == -909);
+    CHECK(ATHandler_stub::ref_count == kATHandler_destructor_ref_ount);
 }
 
 void Test_AT_CellularDevice::test_AT_CellularDevice_close_sms()
@@ -137,7 +137,7 @@ void Test_AT_CellularDevice::test_AT_CellularDevice_close_sms()
     CHECK(ATHandler_stub::ref_count == 1);
 
     dev.close_sms();
-    CHECK(ATHandler_stub::ref_count == -909);
+    CHECK(ATHandler_stub::ref_count == kATHandler_destructor_ref_ount);
 }
 
 void Test_AT_CellularDevice::test_AT_CellularDevice_close_power()
@@ -152,7 +152,7 @@ void Test_AT_CellularDevice::test_AT_CellularDevice_close_power()
     CHECK(ATHandler_stub::ref_count == 1);
 
     dev.close_power();
-    CHECK(ATHandler_stub::ref_count == -909);
+    CHECK(ATHandler_stub::ref_count == kATHandler_destructor_ref_ount);
 }
 
 void Test_AT_CellularDevice::test_AT_CellularDevice_close_sim()
@@ -170,7 +170,7 @@ void Test_AT_CellularDevice::test_AT_CellularDevice_close_sim()
     CHECK(ATHandler_stub::ref_count == 1);
 
     dev.close_sim();
-    CHECK(ATHandler_stub::ref_count == -909);
+    CHECK(ATHandler_stub::ref_count == kATHandler_destructor_ref_ount);
 }
 
 void Test_AT_CellularDevice::test_AT_CellularDevice_close_information()

features/cellular/UNITTESTS/stubs/ATHandler_stub.cpp

@@ -68,7 +68,7 @@ void ATHandler::set_debug(bool debug_on)
 
 ATHandler::~ATHandler()
 {
-    ATHandler_stub::ref_count = -909;
+    ATHandler_stub::ref_count = kATHandler_destructor_ref_ount;
 }
 
 void ATHandler::inc_ref_count()

features/cellular/UNITTESTS/stubs/ATHandler_stub.h

@@ -26,6 +26,8 @@
 static const int kRead_string_table_size = 100;
 static const int kRead_int_table_size = 100;
 static const int kResp_stop_count_default = 100;
+// set reference count to -909 to separate it from zero so we can test that ATHandler is really deleted.
+static const int kATHandler_destructor_ref_ount = -909;
 
 namespace ATHandler_stub {
 extern nsapi_error_t nsapi_error_value;