Fix issues found by coverity (ARMmbed#1889)

- 277905 Unchecked return value from library
- 277906 Unchecked return value from library
- 270649 Uninitialized scalar variable

Author: Arto Kinnunen

source/6LoWPAN/Thread/thread_joiner_application.c

@@ -1140,7 +1140,7 @@ void thread_joiner_pending_config_activate(int8_t interface_id)
     this->active_configuration_ptr->timestamp = pending_active_timestamp;
     // All information is copied from old configuration so if configuration is corrupt we dont change anything.
     this->pending_configuration_ptr = NULL;
-    (void)thread_nvm_store_pending_configuration_remove();
+    thread_nvm_store_pending_configuration_remove();
     configuration_set_copy_mandatory(this->active_configuration_ptr, this->old_active_configuration_ptr);
     link_configuration_update(this->configuration_ptr,this->active_configuration_ptr->data, this->active_configuration_ptr->length);
     link_configuration_trace(this->configuration_ptr);

source/6LoWPAN/Thread/thread_nvm_store.c

@@ -292,7 +292,11 @@ int thread_nvm_store_active_configuration_remove(void)
     }
     char ac_data_path[ACTIVE_CONF_STRING_LEN];
     thread_nvm_store_create_path(ac_data_path, THREAD_NVM_ACTIVE_CONF_FILE);
-    return remove(ac_data_path);
+    int status = remove(ac_data_path);
+    if (status != 0) {
+      return THREAD_NVM_FILE_REMOVE_ERROR;
+    }
+    return THREAD_NVM_FILE_SUCCESS;
 }
 
 int thread_nvm_store_pending_configuration_remove(void)
@@ -302,7 +306,11 @@ int thread_nvm_store_pending_configuration_remove(void)
     }
     char ac_data_path[PENDING_CONF_STRING_LEN];
     thread_nvm_store_create_path(ac_data_path, THREAD_NVM_PENDING_CONF_FILE);
-    return remove(ac_data_path);
+    int status = remove(ac_data_path);
+    if (status != 0) {
+      return THREAD_NVM_FILE_REMOVE_ERROR;
+    }
+    return THREAD_NVM_FILE_SUCCESS;
 }
 
 

source/6LoWPAN/ws/ws_bootstrap.c

@@ -834,8 +834,12 @@ static void ws_bootstrap_pan_advertisement_analyse(struct protocol_interface_inf
         // Saved from unicast IE
         cur->ws_info->parent_info.ws_us = *ws_us;
 
-        // Saved from Pan information
-        cur->ws_info->parent_info.pan_information = pan_information;
+        // Saved from Pan information, do not overwrite pan_version as it is not valid here
+        cur->ws_info->parent_info.pan_information.pan_size = pan_information.pan_size;
+        cur->ws_info->parent_info.pan_information.routing_cost = pan_information.routing_cost;
+        cur->ws_info->parent_info.pan_information.use_parent_bs = pan_information.use_parent_bs;
+        cur->ws_info->parent_info.pan_information.rpl_routing_method = pan_information.rpl_routing_method;
+        cur->ws_info->parent_info.pan_information.version = pan_information.version;
 
         // Saved from message
         cur->ws_info->parent_info.timestamp = data->timestamp;