Rename ssl_locl.h to internal.h

Match the other internal headers.

Change-Id: Iff7e2dd06a1a7bf993053d0464cc15638ace3aaa
Reviewed-on: https://boringssl-review.googlesource.com/4280
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index 1578dba..8d28f38 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -150,7 +150,7 @@
 #include <openssl/rand.h>
 #include <openssl/x509v3.h>
 
-#include "ssl_locl.h"
+#include "internal.h"
 
 /* Some error codes are special. Ensure the make_errors.go script never
  * regresses this. */