Fix typos - mismatching parentheses in comments

src/libcollections/fmt.rs

@@ -429,20 +429,20 @@
 //! For example, these:
 //!
 //! ```
-//! // Hello {arg 0 (x)} is {arg 1 (0.01} with precision specified inline (5)}
+//! // Hello {arg 0 (x)} is {arg 1 (0.01) with precision specified inline (5)}
 //! println!("Hello {0} is {1:.5}", "x", 0.01);
 //!
-//! // Hello {arg 1 (x)} is {arg 2 (0.01} with precision specified in arg 0 (5)}
+//! // Hello {arg 1 (x)} is {arg 2 (0.01) with precision specified in arg 0 (5)}
 //! println!("Hello {1} is {2:.0$}", 5, "x", 0.01);
 //!
-//! // Hello {arg 0 (x)} is {arg 2 (0.01} with precision specified in arg 1 (5)}
+//! // Hello {arg 0 (x)} is {arg 2 (0.01) with precision specified in arg 1 (5)}
 //! println!("Hello {0} is {2:.1$}", "x", 5, 0.01);
 //!
-//! // Hello {next arg (x)} is {second of next two args (0.01} with precision
+//! // Hello {next arg (x)} is {second of next two args (0.01) with precision
 //! //                          specified in first of next two args (5)}
 //! println!("Hello {} is {:.*}",    "x", 5, 0.01);
 //!
-//! // Hello {next arg (x)} is {arg 2 (0.01} with precision
+//! // Hello {next arg (x)} is {arg 2 (0.01) with precision
 //! //                          specified in its predecessor (5)}
 //! println!("Hello {} is {2:.*}",   "x", 5, 0.01);
 //! ```