dmtcp: bump revision to 2212

This versions resolves the problem, where checkpointed application
has huge arguments and environment size.

Signed-off-by: David Abdurachmanov <davidlt@cern.ch>
Merge pull request #258 from davidlt/dmtcp-update-to-rev-2212

[CMSSW_7_0_X] dmtcp: bump revision to 2212