drm/i915: Remove unused ring argument from frontbuffer invalidate and busy functions.

This patch doesn't have any functional change, but organize fruntbuffer
invalidate and busy by removing unecesarry signature argument for ring.

It was unsed on mark_fb_busy and only used on fb_obj_invalidate for the
same ORIGIN_CS usage. So let's clean it a bit

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index be35f04..620e1b7 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -350,7 +350,7 @@
 	if (ret)
 		return ret;
 
-	intel_fb_obj_invalidate(obj, NULL, ORIGIN_CPU);
+	intel_fb_obj_invalidate(obj, ORIGIN_CPU);
 	if (__copy_from_user_inatomic_nocache(vaddr, user_data, args->size)) {
 		unsigned long unwritten;
 
@@ -804,7 +804,7 @@
 
 	offset = i915_gem_obj_ggtt_offset(obj) + args->offset;
 
-	intel_fb_obj_invalidate(obj, NULL, ORIGIN_GTT);
+	intel_fb_obj_invalidate(obj, ORIGIN_GTT);
 
 	while (remain > 0) {
 		/* Operation in this page
@@ -948,7 +948,7 @@
 	if (ret)
 		return ret;
 
-	intel_fb_obj_invalidate(obj, NULL, ORIGIN_CPU);
+	intel_fb_obj_invalidate(obj, ORIGIN_CPU);
 
 	i915_gem_object_pin_pages(obj);
 
@@ -3942,7 +3942,7 @@
 	}
 
 	if (write)
-		intel_fb_obj_invalidate(obj, NULL, ORIGIN_GTT);
+		intel_fb_obj_invalidate(obj, ORIGIN_GTT);
 
 	trace_i915_gem_object_change_domain(obj,
 					    old_read_domains,
@@ -4215,7 +4215,7 @@
 	}
 
 	if (write)
-		intel_fb_obj_invalidate(obj, NULL, ORIGIN_CPU);
+		intel_fb_obj_invalidate(obj, ORIGIN_CPU);
 
 	trace_i915_gem_object_change_domain(obj,
 					    old_read_domains,