cpopen: Fix signal handling in sync points

Change-Id: Id2883091c377c1e4ff9f69b87fc137326b583ab8
Signed-off-by: Saggi Mizrahi <smizrahi@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/15165
Reviewed-by: Zhou Zheng Sheng <zhshzhou@linux.vnet.ibm.com>
Tested-by: Zhou Zheng Sheng <zhshzhou@linux.vnet.ibm.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>