Fix broken links.

Author: waywardmonkeys

src/appendix/humorust.md

@@ -3,7 +3,7 @@
 What's a project without a sense of humor? And frankly some of these are
 enlightening?
 
-- [Weird exprs test](https://github.com/rust-lang/rust/blob/master/src/test/run-pass/weird-exprs.rs)
+- [Weird exprs test](https://github.com/rust-lang/rust/blob/master/src/test/ui/weird-exprs.rs)
 - [Ferris Rap](http://fitzgeraldnick.com/2018/12/13/rust-raps.html)
 - [The Genesis of Generic Germination](https://github.com/rust-lang/rust/pull/53645#issue-210543221)
 - [The Bastion of the Turbofish test](https://github.com/rust-lang/rust/blob/79d8a0fcefa5134db2a94739b1d18daa01fc6e9f/src/test/ui/bastion-of-the-turbofish.rs)