Auto merge of rust-lang#12587 - shandongbinzhou:master, r=Jarcho

Fix typo in comment

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---

*Please write a short comment explaining your change (or "none" for internal only changes)*

changelog: None

clippy_lints/src/serde_api.rs

@@ -9,7 +9,7 @@ declare_clippy_lint! {
     /// Checks for misuses of the serde API.
     ///
     /// ### Why is this bad?
-    /// Serde is very finnicky about how its API should be
+    /// Serde is very finicky about how its API should be
     /// used, but the type system can't be used to enforce it (yet?).
     ///
     /// ### Example