external/boringssl: Sync to b2ff2623a88a65fd4db42d3820f3d8c64e8ab180.

This includes the following changes:

https://boringssl.googlesource.com/boringssl/+log/6d50f475e319de153a43e1dba5a1beca95948c63..b2ff2623a88a65fd4db42d3820f3d8c64e8ab180

Change-Id: I649281e093369d99e863b4882a2ff6a5ad8a64d1
Test: ATP's cts/libcore/gce-net (go/gce-net)
diff --git a/src/decrepit/bio/base64_bio.c b/src/decrepit/bio/base64_bio.c
index 85f30ff..eef4e1a 100644
--- a/src/decrepit/bio/base64_bio.c
+++ b/src/decrepit/bio/base64_bio.c
@@ -526,12 +526,8 @@
   return ret;
 }
 
-static int b64_puts(BIO *b, const char *str) {
-  return b64_write(b, str, strlen(str));
-}
-
 static const BIO_METHOD b64_method = {
-    BIO_TYPE_BASE64, "base64 encoding", b64_write, b64_read, b64_puts,
+    BIO_TYPE_BASE64, "base64 encoding", b64_write, b64_read, NULL /* puts */,
     NULL /* gets */, b64_ctrl,          b64_new,   b64_free, b64_callback_ctrl,
 };