Use ScopedEVP_AEAD_CTX in ImplDispatchTest.AEAD_AES_GCM.

EVP_AEAD_CTX_cleanup is often a no-op now that the data is embedded, but
best to be tidy.

Change-Id: I1ba56e5e36d6e69ae1ba07e40c4a7bda7329fa79
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/37430
Reviewed-by: Adam Langley <agl@google.com>

crypto/impl_dispatch_test.cc

diff --git a/crypto/impl_dispatch_test.cc b/crypto/impl_dispatch_test.cc
index 54ee704..2c3a613 100644
--- a/crypto/impl_dispatch_test.cc
+++ b/crypto/impl_dispatch_test.cc
@@ -105,12 +105,12 @@
         const uint8_t kPlaintext[40] = {1, 2, 3, 4, 0};
         uint8_t ciphertext[sizeof(kPlaintext) + 16];
         size_t ciphertext_len;
-        EVP_AEAD_CTX ctx;
-        ASSERT_TRUE(EVP_AEAD_CTX_init(&ctx, EVP_aead_aes_128_gcm(), kZeros,
+        bssl::ScopedEVP_AEAD_CTX ctx;
+        ASSERT_TRUE(EVP_AEAD_CTX_init(ctx.get(), EVP_aead_aes_128_gcm(), kZeros,
                                       sizeof(kZeros),
                                       EVP_AEAD_DEFAULT_TAG_LENGTH, nullptr));
         ASSERT_TRUE(EVP_AEAD_CTX_seal(
-            &ctx, ciphertext, &ciphertext_len, sizeof(ciphertext), kZeros,
+            ctx.get(), ciphertext, &ciphertext_len, sizeof(ciphertext), kZeros,
             EVP_AEAD_nonce_length(EVP_aead_aes_128_gcm()), kPlaintext,
             sizeof(kPlaintext), nullptr, 0));
       });