[css-backgrounds-3] Fix bug introduced in previous revision.

This fixes incorrect placement of closing parentheses that had
introduced incorrect behavior.

Author: dbaron

css-backgrounds-3/radius-expansion-continuity.html

@@ -300,10 +300,10 @@
         }
       }
       r = {
-        topLeft: radii.topLeft.map((r, idx) => map(r, Math.max(portion.top, portion.left, idx))),
-        topRight: radii.topRight.map((r, idx) => map(r, Math.max(portion.top, portion.right, idx))),
-        bottomLeft: radii.bottomLeft.map((r, idx) => map(r, Math.max(portion.bottom, portion.left, idx))),
-        bottomRight: radii.bottomRight.map((r, idx) => map(r, Math.max(portion.bottom, portion.right, idx))),
+        topLeft: radii.topLeft.map((r, idx) => map(r, Math.max(portion.top, portion.left), idx)),
+        topRight: radii.topRight.map((r, idx) => map(r, Math.max(portion.top, portion.right), idx)),
+        bottomLeft: radii.bottomLeft.map((r, idx) => map(r, Math.max(portion.bottom, portion.left), idx)),
+        bottomRight: radii.bottomRight.map((r, idx) => map(r, Math.max(portion.bottom, portion.right), idx)),
       };
       break;
     }