Revert "drm/i915: Warn if we run out of FIFO space for a mode"

Revert "drm/i915: Warn if we run out of FIFO space for a mode"

This reverts commit b9421ae8f30958deea98d71477b4a77a066856b4.

This warning was so prelevant, even for apparently working machines,
that it was just causing fear, anxiety and panic.

The root cause still remains, so we will add some better debugging when
we focus on fixing it.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=17021
Reported-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>