Revert "Prepare for 2.1.2."

This reverts commit 82e413df because bug fix bf52ed4 (datapath: Check for
backported skb_orphan_frags().) was required.

Signed-off-by: Justin Pettit <jpettit@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Prepare for 2.1.2.

We now increment the version immediately after a release.

Signed-off-by: Justin Pettit <jpettit@nicira.com>