Use _WIN32 rather than HAVE_WINSOCK.

Change-Id: I9855b6fe72e2f2f3a8360c0993a67cb988024ee4
diff --git a/include/utils/FileMap.h b/include/utils/FileMap.h
index f70fc92..afd7bfd 100644
--- a/include/utils/FileMap.h
+++ b/include/utils/FileMap.h
@@ -26,7 +26,7 @@
 
 #if defined(__MINGW32__)
 // Ensure that we always pull in winsock2.h before windows.h
-#ifdef HAVE_WINSOCK
+#if defined(_WIN32)
 #include <winsock2.h>
 #endif
 #include <windows.h>