Use typedef names, not struct names.

Not sure if we want to leave bio.h and bytestring.h's instance as-is, but the
evp.h ones are just baffling.

Change-Id: I485c2e355ba93764da0c4c72c48af48b055a8500
Reviewed-on: https://boringssl-review.googlesource.com/6454
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/include/openssl/bytestring.h b/include/openssl/bytestring.h
index 2fa065e..906e7e8 100644
--- a/include/openssl/bytestring.h
+++ b/include/openssl/bytestring.h
@@ -242,7 +242,7 @@
    * pending length-prefix. */
   size_t offset;
   /* child points to a child CBB if a length-prefix is pending. */
-  struct cbb_st *child;
+  CBB *child;
   /* pending_len_len contains the number of bytes in a pending length-prefix,
    * or zero if no length-prefix is pending. */
   uint8_t pending_len_len;