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/include/sys/socket.h b/libc/include/sys/socket.h
index 22b88cb..9402e70 100644
--- a/libc/include/sys/socket.h
+++ b/libc/include/sys/socket.h
@@ -39,6 +39,7 @@
 #include <linux/types.h>
 #include <linux/compiler.h>
 
+#include <bits/sockaddr_storage.h>
 #include <bits/sa_family_t.h>
 
 __BEGIN_DECLS
@@ -72,15 +73,6 @@
 
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wnullability-completeness"
-struct sockaddr_storage {
-  union {
-    struct {
-      sa_family_t ss_family;
-      char __data[128 - sizeof(sa_family_t)];
-    };
-    void* __align;
-  };
-};
 
 struct linger {
   int l_onoff;