clean up docs for clippy_dump

clippy_lints/src/utils/inspector.rs

@@ -8,15 +8,19 @@ use syntax::ast::{Attribute, MetaItemKind};
 
 /// **What it does:** Dumps every ast/hir node which has the `#[clippy_dump]` attribute
 ///
-/// **Why is this bad?** 😈
-///
-/// **Known problems:** ∅
-///
 /// **Example:**
 /// ```rust
 /// #[clippy_dump]
 /// extern crate foo;
 /// ```
+///
+/// prints
+///
+/// ```
+/// item `foo`
+/// visibility inherited from outer item
+/// extern crate dylib source: "/path/to/foo.so"
+/// ```
 declare_lint! {
     pub DEEP_CODE_INSPECTION,
     Warn,