Revert "Merge pull request #275 from javierguerragiraldez/offload"

This reverts commit 5f783326e5a10e6a6e69a725bbaa95392ef56d8b, reversing
changes made to c2b2ca47c9b4903b3fcdc4814c115f539d36e3eb.
Merge pull request #284 from virtualopensystems/revert_offloading

Revert "Merge pull request #275 from javierguerragiraldez/offload"

TX checksum offload feature was merged prematurely