drm/i915: Update intel_ring_begin() to take a request structure

Now that everything above has been converted to use requests, intel_ring_begin()
can be updated to take a request instead of a ring. This also means that it no
longer needs to lazily allocate a request if no-one happens to have done it
earlier.

For: VIZ-5115
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Tomas Elf <tomas.elf@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
index 3f70904..4445426 100644
--- a/drivers/gpu/drm/i915/intel_overlay.c
+++ b/drivers/gpu/drm/i915/intel_overlay.c
@@ -244,7 +244,7 @@
 	if (ret)
 		return ret;
 
-	ret = intel_ring_begin(ring, 4);
+	ret = intel_ring_begin(req, 4);
 	if (ret) {
 		i915_gem_request_cancel(req);
 		return ret;
@@ -287,7 +287,7 @@
 	if (ret)
 		return ret;
 
-	ret = intel_ring_begin(ring, 2);
+	ret = intel_ring_begin(req, 2);
 	if (ret) {
 		i915_gem_request_cancel(req);
 		return ret;
@@ -353,7 +353,7 @@
 	if (ret)
 		return ret;
 
-	ret = intel_ring_begin(ring, 6);
+	ret = intel_ring_begin(req, 6);
 	if (ret) {
 		i915_gem_request_cancel(req);
 		return ret;
@@ -427,7 +427,7 @@
 		if (ret)
 			return ret;
 
-		ret = intel_ring_begin(ring, 2);
+		ret = intel_ring_begin(req, 2);
 		if (ret) {
 			i915_gem_request_cancel(req);
 			return ret;