Fix leak in ssl_test.

SSL_CIPHER_get_rfc_name still returns an allocated string.

Change-Id: Ie2f14626c1ff22d0ea613b22439b7de5c04c9062
Reviewed-on: https://boringssl-review.googlesource.com/4190
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/ssl_test.cc b/ssl/ssl_test.cc
index d077810..22018bb 100644
--- a/ssl/ssl_test.cc
+++ b/ssl/ssl_test.cc
@@ -413,7 +413,9 @@
   if (cipher == NULL) {
     return false;
   }
-  out->assign(SSL_CIPHER_get_rfc_name(cipher));
+  char *rfc_name = SSL_CIPHER_get_rfc_name(cipher);
+  out->assign(rfc_name);
+  OPENSSL_free(rfc_name);
   return true;
 }