rename WORDS_BIGENDIAN to HOST_WORDS_BIGENDIAN

Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/slirp/tcp.h b/slirp/tcp.h
index c65ed43..c7e3457 100644
--- a/slirp/tcp.h
+++ b/slirp/tcp.h
@@ -50,7 +50,7 @@
 	u_int16_t	th_dport;		/* destination port */
 	tcp_seq	th_seq;			/* sequence number */
 	tcp_seq	th_ack;			/* acknowledgement number */
-#ifdef WORDS_BIGENDIAN
+#ifdef HOST_WORDS_BIGENDIAN
 	u_int	th_off:4,		/* data offset */
 		th_x2:4;		/* (unused) */
 #else