Merge pull request #3435 from gebart/pr/iphc-mcast-8bit

ng_sixlopan_iphc: Multicast decoding 8-bit fix and build fix

sys/net/network_layer/ng_sixlowpan/iphc/ng_sixlowpan_iphc.c

@@ -329,10 +329,10 @@ bool ng_sixlowpan_iphc_decode(ng_pktsnip_t *pkt)
             break;
 
         case IPHC_M_DAC_DAM_M_8:
-            /* ffXX::XX: */
+            /* ff02::XX: */
             ng_ipv6_addr_set_unspecified(&ipv6_hdr->dst);
             ipv6_hdr->dst.u8[0] = 0xff;
-            ipv6_hdr->dst.u8[1] = iphc_hdr[payload_offset++];
+            ipv6_hdr->dst.u8[1] = 0x02;
             ipv6_hdr->dst.u8[15] = iphc_hdr[payload_offset++];
             break;
 
@@ -499,7 +499,8 @@ bool ng_sixlowpan_iphc_encode(ng_pktsnip_t *pkt)
         }
 
         if ((src_ctx != NULL) || ng_ipv6_addr_is_link_local(&(ipv6_hdr->src))) {
-            eui64_t iid = { 0 };
+            eui64_t iid;
+            iid.uint64.u64 = 0;
 
             if ((netif_hdr->src_l2addr_len == 2) ||
                 (netif_hdr->src_l2addr_len == 4) ||
@@ -556,7 +557,7 @@ bool ng_sixlowpan_iphc_encode(ng_pktsnip_t *pkt)
             (ipv6_hdr->dst.u32[1].u32 == 0) &&
             (ipv6_hdr->dst.u16[4].u16 == 0)) {
             /* if multicast address is of format ff02::XX */
-            if ((ipv6_hdr->dst.u8[1] == 2) &&
+            if ((ipv6_hdr->dst.u8[1] == 0x02) &&
                 (ipv6_hdr->dst.u32[2].u32 == 0) &&
                 (ipv6_hdr->dst.u16[6].u16 == 0) &&
                 (ipv6_hdr->dst.u8[14] == 0)) {