openssl: compatibility with BoringSSL

Change-Id: Ic5a2bacf9e8756c24f78b4d59a50cfec460ba5f2
diff --git a/src/openssl.c b/src/openssl.c
index f10f292..53fe9ed 100644
--- a/src/openssl.c
+++ b/src/openssl.c
@@ -411,7 +411,11 @@
     aes_ctr_cipher->key_len = keylen;
     aes_ctr_cipher->iv_len = 16;
     aes_ctr_cipher->init = aes_ctr_init;
+#ifdef OPENSSL_IS_BORINGSSL
+    aes_ctr_cipher->cipher = aes_ctr_do_cipher;
+#else
     aes_ctr_cipher->do_cipher = aes_ctr_do_cipher;
+#endif
     aes_ctr_cipher->cleanup = aes_ctr_cleanup;
 #endif