drm/i915: Use a pipe variable to cycle through the pipes

I recently fumbled a patch because I wrote twice num_sprites[i], and it
was the right thing to do in only 50% of the cases.

This patch ensures I need to write num_sprites[pipe], ie it should be
self-documented that it's per-pipe number of sprites without having to
look at what is 'i' this time around.

It's all a lame excuse, but it does make it harder to redo the same
mistake.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 227f660..1ab9e3f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -10981,7 +10981,8 @@
 void intel_modeset_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	int i, j, ret;
+	int j, ret;
+	enum pipe pipe;
 
 	drm_mode_config_init(dev);
 
@@ -11018,13 +11019,13 @@
 		      INTEL_INFO(dev)->num_pipes,
 		      INTEL_INFO(dev)->num_pipes > 1 ? "s" : "");
 
-	for_each_pipe(i) {
-		intel_crtc_init(dev, i);
+	for_each_pipe(pipe) {
+		intel_crtc_init(dev, pipe);
 		for (j = 0; j < INTEL_INFO(dev)->num_sprites; j++) {
-			ret = intel_plane_init(dev, i, j);
+			ret = intel_plane_init(dev, pipe, j);
 			if (ret)
 				DRM_DEBUG_KMS("pipe %c sprite %c init failed: %d\n",
-					      pipe_name(i), sprite_name(i, j), ret);
+					      pipe_name(pipe), sprite_name(pipe, j), ret);
 		}
 	}