Fixed Echo request handle

Address select steering address from dst->src.

Author: Juha Heiskanen

source/Common_Protocols/icmpv6.c

@@ -325,12 +325,12 @@ static buffer_t *icmpv6_echo_request_handler(buffer_t *buf)
 
     if (addr_is_ipv6_multicast(buf->dst_sa.address)) {
         const uint8_t *ipv6_ptr;
+        memcpy(buf->dst_sa.address, buf->src_sa.address, 16);
         ipv6_ptr = addr_select_source(cur, buf->dst_sa.address, 0);
         if (!ipv6_ptr) {
             tr_debug("No address");
             return buffer_free(buf);
         }
-        memcpy(buf->dst_sa.address, buf->src_sa.address, 16);
         memcpy(buf->src_sa.address, ipv6_ptr, 16);
     } else {
         memswap(buf->dst_sa.address, buf->src_sa.address, 16);