Removed dead-code under #if LINUX_VERSION_CODE ...

- All > 2.6.X are assumed true and the #else parts removed.
- All < 3.0 are removed and their #else parts retained.
- Note: there are some cases of < 3.4, but they are retained in case 3.2
  support was later added.

Signed-off-by: Shahbaz Youssefi <ShabbyX@gmail.com>