drm/i915: spelling fixes for frontbuffer tracking kerneldoc

Oh well.

v2: Fix one more spelling fail Paulo spotted.

Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 072e69f..f14f456 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -819,7 +819,7 @@
 void intel_frontbuffer_flush(struct drm_device *dev,
 			     unsigned frontbuffer_bits);
 /**
- * intel_frontbuffer_flip - prepare frontbuffer flip
+ * intel_frontbuffer_flip - synchronous frontbuffer flip
  * @dev: DRM device
  * @frontbuffer_bits: frontbuffer plane tracking bits
  *