drm/i915: Rename unpin_count to pin_count

We increase it when we pin, so for the casual reader
rename it to cause less confusion.

Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Thomas Daniel <thomas.daniel@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 56fd2b8..de304d7 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -765,7 +765,7 @@
 	struct {
 		struct drm_i915_gem_object *state;
 		struct intel_ringbuffer *ringbuf;
-		int unpin_count;
+		int pin_count;
 	} engine[I915_NUM_RINGS];
 
 	struct list_head link;