net: fix accidental overwrite of more than just the address

Commit 0b783341 accidentally overwrote more than just the
address, causing garbage in the connection part.

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/engines/net.c b/engines/net.c
index 8b85a88..dd06861 100644
--- a/engines/net.c
+++ b/engines/net.c
@@ -913,10 +913,10 @@
 
 	if (is_ipv6(o)) {
 		af = AF_INET6;
-		dst = &nd->addr6;
+		dst = &nd->addr6.sin6_addr;
 	} else {
 		af = AF_INET;
-		dst = &nd->addr;
+		dst = &nd->addr.sin_addr;
 	}
 
 	if (fio_fill_addr(td, host, af, dst, &res))