Fixes errors related to gnrc_netreg_entry

 - Fixes initialisation error
 - Corrects access to pid

Author: JerryMain

task-09/udp.c

@@ -28,7 +28,7 @@
 #include "timex.h"
 #include "xtimer.h"
 
-static gnrc_netreg_entry_t server = { NULL, GNRC_NETREG_DEMUX_CTX_ALL, KERNEL_PID_UNDEF };
+static gnrc_netreg_entry_t server = GNRC_NETREG_ENTRY_INIT_PID(GNRC_NETREG_DEMUX_CTX_ALL, KERNEL_PID_UNDEF);
 
 
 static void send(char *addr_str, char *port_str, char *data, unsigned int num,
@@ -93,7 +93,7 @@ static void start_server(char *port_str)
     uint16_t port;
 
     /* check if server is already running */
-    if (server.pid != KERNEL_PID_UNDEF) {
+    if (server.target.pid != KERNEL_PID_UNDEF) {
         printf("Error: server already running on port %" PRIu32 "\n",
                server.demux_ctx);
         return;
@@ -105,7 +105,7 @@ static void start_server(char *port_str)
         return;
     }
     /* start server (which means registering pktdump for the chosen port) */
-    server.pid = gnrc_pktdump_pid;
+    server.target.pid = gnrc_pktdump_pid;
     server.demux_ctx = (uint32_t)port;
     gnrc_netreg_register(GNRC_NETTYPE_UDP, &server);
     printf("Success: started UDP server on port %" PRIu16 "\n", port);
@@ -114,13 +114,13 @@ static void start_server(char *port_str)
 static void stop_server(void)
 {
     /* check if server is running at all */
-    if (server.pid == KERNEL_PID_UNDEF) {
+    if (server.target.pid == KERNEL_PID_UNDEF) {
         printf("Error: server was not running\n");
         return;
     }
     /* stop server */
     gnrc_netreg_unregister(GNRC_NETTYPE_UDP, &server);
-    server.pid = KERNEL_PID_UNDEF;
+    server.target.pid = KERNEL_PID_UNDEF;
     puts("Success: stopped UDP server");
 }