Added return value (success / failure ) to nimble_port_init

porting/examples/dummy/main.c

@@ -21,7 +21,7 @@
 
 int main(int argc, char **argv)
 {
-    nimble_port_init();
+    int ret = nimble_port_init();
 
-    return 0;
+    return ret;
 }

porting/examples/linux/main.c

@@ -66,8 +66,8 @@ int main(int argc, char *argv[])
         ble_hci_sock_set_device(atoi(argv[1]));
     }
 
-    nimble_port_init();
     ble_hci_sock_init();
+    ret = nimble_port_init();
 
     /* This example provides GATT Alert service */
     ble_svc_gap_init();

porting/examples/linux_blemesh/main.c

@@ -79,8 +79,8 @@ int main(int argc, char *argv[])
         ble_hci_sock_set_device(atoi(argv[1]));
     }
 
-    nimble_port_init();
     ble_hci_sock_init();
+    ret = nimble_port_init();
 
     ble_svc_gap_init();
     ble_svc_gatt_init();

porting/examples/nuttx/main.c

@@ -87,7 +87,12 @@ int main(int argc, char *argv[])
 #endif
 
     printf("port init\n");
-    nimble_port_init();
+
+    ret = nimble_port_init();
+    if (ret != 0) {
+        printf(" Failed to init nimble %d \n", ret);
+	return ret;
+    }
 
     printf("hci init\n");
     ble_hci_sock_init();