address comments and run doc example again to update result

Signed-off-by: Xintao <[email protected]>

Author: hunterlxt

src/lib.rs

@@ -140,10 +140,10 @@
 //! FAILPOINTS=p0=return cargo run --features fail/failpoints
 //!     Finished dev [unoptimized + debuginfo] target(s) in 0.01s
 //!      Running `target/debug/failpointtest`
-//! Global registry: [("p1", "sleep(100)")]
+//! Global registry: [("p0", "return"), ("p1", "sleep(100)")]
 //! Local registry: [("p0", "pause")]
 //! Local registry: []
-//! Global registry: [("p1", "sleep(100)")]
+//! Global registry: [("p0", "return"), ("p1", "sleep(100)")]
 //! ```
 //!
 //! In this example, program update global registry with environment variable first.