drm/i915: Remove obsolete seqno parameter from 'i915_add_request'

There is no longer any need to retrieve a seqno value from an i915_add_request()
call. The calling code already knows which request structure is being processed
(it can only be ring->OLR). And as the request itself is now used in preference
to the basic seqno value, the latter is now redundant in this situation.

For: VIZ-4377
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Thomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_gem.c

@@ -1164,7 +1164,7 @@ i915_gem_check_olr(struct drm_i915_gem_request *req)
 
 	ret = 0;
 	if (req == req->ring->outstanding_lazy_request)
-		ret = i915_add_request(req->ring, NULL);
+		ret = i915_add_request(req->ring);
 
 	return ret;
 }
@@ -2412,8 +2412,7 @@ i915_gem_get_seqno(struct drm_device *dev, u32 *seqno)
 
 int __i915_add_request(struct intel_engine_cs *ring,
 		       struct drm_file *file,
-		       struct drm_i915_gem_object *obj,
-		       u32 *out_seqno)
+		       struct drm_i915_gem_object *obj)
 {
 	struct drm_i915_private *dev_priv = ring->dev->dev_private;
 	struct drm_i915_gem_request *request;
@@ -2512,8 +2511,6 @@ int __i915_add_request(struct intel_engine_cs *ring,
 			   round_jiffies_up_relative(HZ));
 	intel_mark_busy(dev_priv->dev);
 
-	if (out_seqno)
-		*out_seqno = request->seqno;
 	return 0;
 }