all.py: remove explicit additions of -auto to test command lines

Patch c6fc8b36b948a7c2 modified the python PiglitGLTESt class (the one
used by non-glean, non-shader_test, non-glsl_parser_test tests) to
automatically add -auto to all tests, and -fbo to concurrent tests.

I did a really poor job of looking for tests that contained -auto in
them when that patch was added because of the add_plain_test and
add_concurrent_test wrappers. This patch corrects that oversight by
remove tests that explicitly add -auto.

It does not remove tests that explicitly set -fbo, because the tests
that are doing that are not setting run_concurrent=True, so -fbo isn't
being added to their command lines automatically.

TODO: Test for regressions.