Fix problematic query in TOutputGLSLBase::visitDeclaration. There was an invalid derefernce that for some reason was not caught on the bots. Bug: angleproject:2456 No-Try: True Change-Id: I088e9671122fd25077027cb2eb577aa099fdcacf Reviewed-on: https://chromium-review.googlesource.com/1015287 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Luc Ferron <lucferron@chromium.org>