Update clippy to cffb416

Manishearth · Manishearth · commit e16dce07b796 · 2019-04-07T14:21:47.000-07:00
diff --git a/src/tools/clippy b/src/tools/clippy
@@ -1 +1 @@
-Subproject commit 92612c9de159889f77f05855a77482ee1d895f51
+Subproject commit cffb416d8951af22bc921b0f2870ddd6bb9d1104
