external/boringssl: Sync to 8ca0b41.

This includes the following changes:

https://boringssl.googlesource.com/boringssl/+log/9d908ba519f2cfe5e21561bdee3e224b94d14a89..8ca0b4127da11d766067ea6ec4122017ba0edb0e

Change-Id: I732653bc8fcba70707c615f8731ca75397a08736
diff --git a/src/decrepit/bio/base64_bio.c b/src/decrepit/bio/base64_bio.c
index 2056138..8415bfe 100644
--- a/src/decrepit/bio/base64_bio.c
+++ b/src/decrepit/bio/base64_bio.c
@@ -452,7 +452,7 @@
     case BIO_CTRL_WPENDING: /* More to write in buffer */
       assert(ctx->buf_len >= ctx->buf_off);
       ret = ctx->buf_len - ctx->buf_off;
-      if ((ret == 0) && (ctx->encode != B64_NONE) && (ctx->base64.num != 0)) {
+      if ((ret == 0) && (ctx->encode != B64_NONE) && (ctx->base64.data_used != 0)) {
         ret = 1;
       } else if (ret <= 0) {
         ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
@@ -484,7 +484,7 @@
           ctx->tmp_len = 0;
           goto again;
         }
-      } else if (ctx->encode != B64_NONE && ctx->base64.num != 0) {
+      } else if (ctx->encode != B64_NONE && ctx->base64.data_used != 0) {
         ctx->buf_off = 0;
         EVP_EncodeFinal(&(ctx->base64), (uint8_t *)ctx->buf, &(ctx->buf_len));
         /* push out the bytes */