Fix whitespace issues that tidy caught

Author: vcfxb

library/core/src/str/mod.rs

@@ -1161,7 +1161,7 @@ impl str {
     /// function or closure that determines if a character matches.
     ///
     /// Note that there is a footgun to this method when using a slice of [`char`]s.
-    /// Some users may expect that a slice of chars will behave similarly to a `&str` with this method. 
+    /// Some users may expect that a slice of chars will behave similarly to a `&str` with this method.
     /// That is not currently the case. When you pass a slice of [`char`]s to this method, it will return true
     /// if any of the [`char`]s in the slice is the first [`char`] of this string slice. It does not work for
     /// sequentially comparing a slice of [`char`]s to a string slice. See the second example below.
@@ -1177,11 +1177,11 @@ impl str {
     /// assert!(bananas.starts_with("bana"));
     /// assert!(!bananas.starts_with("nana"));
     /// ```
-    /// 
+    ///
     /// ```
     /// let bananas = "bananas";
-    /// 
-    /// // Note that both of these assert successfully. 
+    ///
+    /// // Note that both of these assert successfully.
     /// assert!(bananas.starts_with(&['b', 'a', 'n', 'a']));
     /// assert!(bananas.starts_with(&['a', 'b', 'c', 'd']));
     /// ```