Fix linknamespace parallel test failures [committed]

[Florian Weimer]

On 11/03/2016 11:47 PM, Joseph Myers wrote:
> 2016-11-03  Joseph Myers  <joseph@codesourcery.com>
>
> 	* conform/Makefile ($(linknamespace-header-tests)): Also depend on
> 	$(linknamespace-symlists-tests).

I tried this on a medium-to-large x86_64 machine (120 cores/240 
threads), and I had linknamespace failures before this commit, which are 
gone after it.  Thanks!

Florian