Fix non-noise cpplint errors in //crypto.

crypto/aead.cc

Index: crypto/aead.cc
diff --git a/crypto/aead.cc b/crypto/aead.cc
index a0ef250d83d154adda84d03ab40eee8d6a276238..7b9bb52e3e9286d71a83a6773e60b14210e25573 100644
--- a/crypto/aead.cc
+++ b/crypto/aead.cc
@@ -120,4 +120,4 @@ size_t Aead::NonceLength() const {
   return EVP_AEAD_nonce_length(aead_);
 }
 
-}  // namespace
+}  // namespace crypto