This call is a no-op. The shader parser is intended to almost always
recover from errors, so including it doesn't clarify the code either.
It's simpler to remove it entirely.

BUG=angleproject:911
TEST=angle_unittests

Change-Id: I0feae097c2807c8e9559672e7a3d50a2fc4fbdea
Reviewed-on: https://chromium-review.googlesource.com/367040
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>