Remove <sys/_types.h>.

Bug: 12213562
Change-Id: I0d10664f9da60739bdbad0408be0dd61eea3c1fe
diff --git a/libc/include/sys/un.h b/libc/include/sys/un.h
index f89ead3..65ffbdcf 100644
--- a/libc/include/sys/un.h
+++ b/libc/include/sys/un.h
@@ -28,8 +28,7 @@
 #ifndef _SYS_UN_H_
 #define _SYS_UN_H_
 
-#include <sys/_types.h>
-typedef __sa_family_t sa_family_t;
+typedef unsigned short sa_family_t;
 
 #include <linux/un.h>