README: fix lit count line

It looks like after changing to "there are more than 120 lints", an older PR was merged
and resolving merge conflicts this was changed back to "there are 123 lints" causing the update-script to silently fail.

Changed back the README.md back to the new format fixes the problem.

Author: matthiaskrgr

README.md

@@ -5,7 +5,7 @@
 
 A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code.
 
-[There are 362 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
+[There are over 350 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
 
 We have a bunch of lint categories to allow you to choose how much Clippy is supposed to ~~annoy~~ help you: