Extend the kernel version check to also accept Linux 3.x as valid.

Signed-off-by: Alexander Schreiber <als@google.com>
Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>
(cherry picked from commit 1bf72492)

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>