drm/i915: properly check for pipe count
drm/i915: properly check for pipe count

As suggested by Chris Wilson and Daniel Vetter, this chunk of code can be
simplified with a more simple check.

Also, as noticed by Jesse Barnes, it is worth mentioning that plane is an
enum and num_pipe is an int, so we could be more paranoid here about those
validation checks eventually.

CC: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>
CC: Chris Wilson <711c73f64afdce07b7e38039a96d2224209e9a6c@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <bc7add126c2dbb8382bf1c28ac262b9363a32706@virtuousgeek.org>
Signed-off-by: Eugeni Dodonov <8cab21ffd2ceb3ee06d75e34eb970dfea6bd7cc6@intel.com>
Signed-off-by: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas