Use separate buffers for encrypted and decrypted content in print-esp.c

Use separate buffers for encrypted and decrypted content in print-esp.c

The EVP_Cipher function should not be called with the same buffer as
input and output. It works fine on most architectures, but fails on
PowerPC. There is also a second problem, that we write the output to a
const buffer, but this issue is not addressed with this PR.