samples: net: azure_iot_hub: Fix bug in response to direct method

The response payload size was not set correctly resulting in an
invalid json response. The size set was the size of the pointer (4)
and not the string content.

Signed-off-by: Jan Tore Guggedal <[email protected]>

Author: jtguggedal

samples/net/azure_iot_hub/src/main.c

@@ -313,7 +313,7 @@ static void send_event(struct k_work *work)
 static void direct_method_handler(struct k_work *work)
 {
 	int err;
-	static char *response = "{\"it\":\"worked\"}";
+	static const char response[] = "{\"it\":\"worked\"}";
 
 	/* Status code 200 indicates successful execution of direct method. */
 	struct azure_iot_hub_result result = {
@@ -322,7 +322,7 @@ static void direct_method_handler(struct k_work *work)
 			.size = strlen(method_data.request_id),
 		},
 		.status = 200,
-		.payload.ptr = response,
+		.payload.ptr = (char *)response,
 		.payload.size = sizeof(response) - 1,
 	};
 	bool led_state = strncmp(method_data.payload, "0", 1) ? 1 : 0;