cr-service: set cr_errno if cpuinfo dump is not supported

Right now only x86 supports dumping and checking the cpuinfo. All other
architectures are returning -ENOTSUP and thus p.haul fails if started
without '--force'. This adds -ENOTSUP to the RPC field cr_errno in the
case cpuinfo dumping and checking failed with this return code.

Signed-off-by: Adrian Reber <areber@redhat.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>