Use the canonical idiom for sockaddr_storage.

This works out a bit silly/ugly because the bits/ header file has the
wrong name, so I've also changed the map from kernel struct to boolean
to be a map from kernel struct to filename. That not only fixes this,
it's a bit more readable too. (Just yesterday, when I had no real reason
to change it, I was asking myself "why is this a boolean?"!)

Bug: http://b/236042740
Test: treehugger
Change-Id: I3eee25b493ea97d46cc5dc5fde07f7c5e77d2a46
diff --git a/libc/kernel/uapi/linux/socket.h b/libc/kernel/uapi/linux/socket.h
index 936f44a..27890a4 100644
--- a/libc/kernel/uapi/linux/socket.h
+++ b/libc/kernel/uapi/linux/socket.h
@@ -6,17 +6,9 @@
  */
 #ifndef _UAPI_LINUX_SOCKET_H
 #define _UAPI_LINUX_SOCKET_H
+#include <bits/sockaddr_storage.h>
 #define _K_SS_MAXSIZE 128
 typedef unsigned short __kernel_sa_family_t;
-struct __kernel_sockaddr_storage {
-  union {
-    struct {
-      __kernel_sa_family_t ss_family;
-      char __data[_K_SS_MAXSIZE - sizeof(unsigned short)];
-    };
-    void * __align;
-  };
-};
 #define SOCK_SNDBUF_LOCK 1
 #define SOCK_RCVBUF_LOCK 2
 #define SOCK_BUF_LOCK_MASK (SOCK_SNDBUF_LOCK | SOCK_RCVBUF_LOCK)