Revert "i965: Reinstate max-index paranoia"

Revert "i965: Reinstate max-index paranoia"

This reverts commit b4cbd2b312d53a50603e2cda925711bc9def4517.

It looked like a safe sanity check. It missed the issue of the start of
the buffer not being at 0, but even that was not enough to explain why
setting the max vertex index caused glyphs to be dropped from the game
'Achron'.

Instead, the issue appears to be related to the use of the vertex bias
and so we would need to re-emit the max-index every time we adjusted the
bias, so re-emitting the relocations and defeating the original
optimisation.

Reported-and-tested-by: Thomas Jones <thomas.jones@utoronto.ca>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=35163
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>