drm/i915: Kerneldoc typo s/rps/rps_client/

Update the kerneldoc parameter name to match the real parameter name.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20171109140644.10805-1-chris@chris-wilson.co.ukReviewed-by: Matthew Auld <matthew.auld@intel.com>

drivers/gpu/drm/i915/i915_gem.c

@@ -538,7 +538,7 @@ i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
  * @obj: i915 gem object
  * @flags: how to wait (under a lock, for all rendering or just for writes etc)
  * @timeout: how long to wait
- * @rps: client (user process) to charge for any waitboosting
+ * @rps_client: client (user process) to charge for any waitboosting
  */
 int
 i915_gem_object_wait(struct drm_i915_gem_object *obj,