[sksg] Fix inval rect mapping

Return false from mapRect() doesn't mean the op failed.

TBR=
Change-Id: I0582fde3efaa792010f27e3684cfe9c4332e29dc
Reviewed-on: https://skia-review.googlesource.com/90021
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
diff --git a/experimental/sksg/SkSGInvalidationController.cpp b/experimental/sksg/SkSGInvalidationController.cpp
index 114d724..4b133d8 100644
--- a/experimental/sksg/SkSGInvalidationController.cpp
+++ b/experimental/sksg/SkSGInvalidationController.cpp
@@ -17,8 +17,8 @@
 void InvalidationController::inval(const SkRect& r, const SkMatrix& ctm) {
     SkTCopyOnFirstWrite<SkRect> rect(r);
 
-    if (!ctm.isIdentity() && !ctm.mapRect(rect.writable())) {
-        *rect.writable() = SkRect::MakeLTRB(SK_ScalarMin, SK_ScalarMin, SK_ScalarMax, SK_ScalarMax);
+    if (!ctm.isIdentity()) {
+        ctm.mapRect(rect.writable());
     }
 
     fRects.push(*rect);