Align prototype & implementation of enet_tasklet_disconnect & friends

Rework of #8698

Signed-off-by: Alastair D'Silva <[email protected]>

Author: deece

features/nanostack/mbed-mesh-api/source/NanostackEthernetInterface.cpp

@@ -97,5 +97,8 @@ nsapi_error_t NanostackEthernetInterface::do_initialize()
 
 nsapi_error_t Nanostack::EthernetInterface::bringdown()
 {
-    return enet_tasklet_disconnect(true);
+    if (enet_tasklet_disconnect(true)) {
+        return NSAPI_ERROR_DEVICE_ERROR;
+    }
+    return NSAPI_ERROR_OK;
 }

features/nanostack/mbed-mesh-api/source/ethernet_tasklet.c

@@ -294,7 +294,7 @@ int8_t enet_tasklet_disconnect(bool send_cb)
         if (tasklet_data_ptr->network_interface_id != INVALID_INTERFACE_ID) {
             status = arm_nwk_interface_down(tasklet_data_ptr->network_interface_id);
             tasklet_data_ptr->network_interface_id = INVALID_INTERFACE_ID;
-            if (send_cb == true) {
+            if (send_cb) {
                 enet_tasklet_network_state_changed(MESH_DISCONNECTED);
             }
         }

features/nanostack/mbed-mesh-api/source/include/enet_tasklet.h

@@ -17,6 +17,7 @@
 #ifndef ENET_TASKLET_H
 #define ENET_TASKLET_H
 
+#include "mesh_interface_types.h"
 
 #ifdef __cplusplus
 extern "C" {