drm/i915: don't handle PIPE_LEGACY_BLC_EVENT_STATUS on vlv

This is for legacy legacy stuff, and checking with the leftover
pipe from the previous loop is propably not what we want. Since
pipe == 2 after the loop ... Then we only assing a variable and do
nothing with it.

Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>