i965: Fix shadowing of 'height' parameter

i965: Fix shadowing of 'height' parameter

The nested declaration of 'height' shadows a parameter and uses
uninitialized memory. Fix by renaming to 'plane_height' which also makes
the code clearer.

This would typically break the bo size computation, but we don't use
that except when mmaping, and we don't mmap YUV buffers much.

Signed-off-by: Kristian Høgsberg Kristensen <krh@bitplanet.net>
Reported-by: Mathias Fröhlich <Mathias.Froehlich@gmx.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>