gnrc: fix cppcheck warnings

sys/net/gnrc/network_layer/ipv6/netif/gnrc_ipv6_netif.c

@@ -792,6 +792,8 @@ void gnrc_ipv6_netif_init_by_dev(void)
     kernel_pid_t ifs[GNRC_NETIF_NUMOF];
     size_t ifnum = gnrc_netif_get(ifs);
 #ifdef MODULE_GNRC_SIXLOWPAN_ND_BORDER_ROUTER
+    /* cppcheck-suppress unreadVariable
+     * (reason: cppcheck bug. abr_init is read in if below) */
     bool abr_init = false;
 #endif
 

sys/net/gnrc/routing/rpl/p2p/gnrc_rpl_p2p.c

@@ -48,9 +48,8 @@ const uint8_t gnrc_rpl_p2p_lifetime_lookup[4] = { 1, 4, 16, 64 };
 
 void gnrc_rpl_p2p_update(void)
 {
-    gnrc_rpl_p2p_ext_t *p2p_ext;
     for (uint8_t i = 0; i < GNRC_RPL_P2P_EXTS_NUMOF; ++i) {
-        p2p_ext = &gnrc_rpl_p2p_exts[i];
+        gnrc_rpl_p2p_ext_t *p2p_ext = &gnrc_rpl_p2p_exts[i];
         if ((p2p_ext->state) && (p2p_ext->lifetime_sec > 0)) {
             p2p_ext->lifetime_sec -= GNRC_RPL_LIFETIME_UPDATE_STEP;
             if (p2p_ext->lifetime_sec <= 0) {

sys/net/gnrc/sock/udp/gnrc_sock_udp.c

@@ -69,10 +69,9 @@ static bool _dyn_port_used(uint16_t port)
  */
 static uint16_t _get_dyn_port(sock_udp_t *sock)
 {
-    uint16_t port;
     unsigned count = GNRC_SOCK_DYN_PORTRANGE_NUM;
     do {
-        port = GNRC_SOCK_DYN_PORTRANGE_MIN +
+        uint16_t port = GNRC_SOCK_DYN_PORTRANGE_MIN +
                (_dyn_port_next * GNRC_SOCK_DYN_PORTRANGE_OFF) % GNRC_SOCK_DYN_PORTRANGE_NUM;
         _dyn_port_next++;
         if ((sock == NULL) || (sock->flags & SOCK_FLAGS_REUSE_EP) ||