bug#19599: strace test suite failures

[Mark H Weaver]

The strace builds on both x86_64 and i686 intermittently fail,
apparently based on 'uname' output which in turn depends on which build
slave was used.  See:

  http://hydra.gnu.org/build/196334/log/tail-reload

--8<---------------cut here---------------start------------->8---
starting phase `check'
make  check-recursive
make[1]: Entering directory '/tmp/nix-build-strace-4.7.drv-0/strace-4.7'
Making check in tests
make[2]: Entering directory '/tmp/nix-build-strace-4.7.drv-0/strace-4.7/tests'
make  check-TESTS
make[3]: Entering directory '/tmp/nix-build-strace-4.7.drv-0/strace-4.7/tests'
../strace: Bad OS release string: '3.14-2-amd64'
ptrace_setoptions: framework failure: ../strace is not available
FAIL: ptrace_setoptions
../strace: Bad OS release string: '3.14-2-amd64'
strace-f: framework failure: ../strace is not available
FAIL: strace-f
===================
2 of 2 tests failed
===================
--8<---------------cut here---------------end--------------->8---

       Mark