OpenSSL: Fix a memory leak in CMAC

The OpenSSL 3.0 (or newer) version of omac1_aes_vector() did not free
the EVP_MAC. This resulted in a memory leak that shows up in a bit
strange way in valgrind reports and because of that, was not caught
during automated testing.

Fixes: 0c61f6234f ("OpenSSL: Implement CMAC using the EVP_MAC API")
Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>

src/crypto/crypto_openssl.c

@@ -1835,6 +1835,7 @@ int omac1_aes_vector(const u8 *key, size_t key_len, size_t num_elem,
 	ret = 0;
 fail:
 	EVP_MAC_CTX_free(ctx);
+	EVP_MAC_free(emac);
 	return ret;
 #else /* OpenSSL version >= 3.0 */
 	CMAC_CTX *ctx;