Use _WIN32 rather than HAVE_WINSOCK.

Change-Id: I9855b6fe72e2f2f3a8360c0993a67cb988024ee4
diff --git a/include/cutils/sockets.h b/include/cutils/sockets.h
index 07d1351..2d3c743 100644
--- a/include/cutils/sockets.h
+++ b/include/cutils/sockets.h
@@ -23,7 +23,7 @@
 #include <string.h>
 #include <stdbool.h>
 
-#ifdef HAVE_WINSOCK
+#if defined(_WIN32)
 #include <winsock2.h>
 typedef int  socklen_t;
 #else