Auto merge of rust-lang#7382 - matthiaskrgr:config_name, r=flip1995

Fix wrong config option being suggested for deprecated wrong_pub_self_convention lint

Problem:
for code like
````rust
#![warn(clippy::wrong_pub_self_convention)]
fn main() {
    println!("Hello, world!");
}
````
clippy will issue a warning to use a clippy.toml option instead:

````
warning: lint `clippy::wrong_pub_self_convention` has been removed: set the `avoid_breaking_exported_api` config option to `false` to enable the `wrong_self_convention` lint for public items
 --> src/main.rs:2:9
  |
2 | #![warn(clippy::wrong_pub_self_convention)]
  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(renamed_and_removed_lints)]` on by default
````

But using the lint name as seen in the warning message
`echo "avoid_breaking_exported_api = true\n" > clippy.toml`

Will cause an error:
````
error: error reading Clippy's configuration file `/tmp/clippytest/clippy.toml`: unknown field `avoid_breaking_exported_api`, expected one of `avoid-breaking-exported-api`, ...
````

Replace the underscores with dashes in the deprecation message.

changelog: avoid_breaking_exported_api: suggest correct clippy config toml option in the deprecation message

Author: bors

clippy_lints/src/deprecated_lints.rs

@@ -149,7 +149,7 @@ declare_deprecated_lint! {
     /// enables the `enum_variant_names` lint for public items.
     /// ```
     pub PUB_ENUM_VARIANT_NAMES,
-    "set the `avoid_breaking_exported_api` config option to `false` to enable the `enum_variant_names` lint for public items"
+    "set the `avoid-breaking-exported-api` config option to `false` to enable the `enum_variant_names` lint for public items"
 }
 
 declare_deprecated_lint! {
@@ -158,5 +158,5 @@ declare_deprecated_lint! {
     /// **Deprecation reason:** The `avoid_breaking_exported_api` config option was added, which
     /// enables the `wrong_self_conversion` lint for public items.
     pub WRONG_PUB_SELF_CONVENTION,
-    "set the `avoid_breaking_exported_api` config option to `false` to enable the `wrong_self_convention` lint for public items"
+    "set the `avoid-breaking-exported-api` config option to `false` to enable the `wrong_self_convention` lint for public items"
 }

clippy_lints/src/lib.rs

@@ -484,11 +484,11 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     );
     store.register_removed(
         "clippy::pub_enum_variant_names",
-        "set the `avoid_breaking_exported_api` config option to `false` to enable the `enum_variant_names` lint for public items",
+        "set the `avoid-breaking-exported-api` config option to `false` to enable the `enum_variant_names` lint for public items",
     );
     store.register_removed(
         "clippy::wrong_pub_self_convention",
-        "set the `avoid_breaking_exported_api` config option to `false` to enable the `wrong_self_convention` lint for public items",
+        "set the `avoid-breaking-exported-api` config option to `false` to enable the `wrong_self_convention` lint for public items",
     );
     // end deprecated lints, do not remove this comment, it’s used in `update_lints`
 

tests/ui/deprecated.stderr

@@ -84,13 +84,13 @@ error: lint `clippy::filter_map` has been removed: this lint has been replaced b
 LL | #[warn(clippy::filter_map)]
    |        ^^^^^^^^^^^^^^^^^^
 
-error: lint `clippy::pub_enum_variant_names` has been removed: set the `avoid_breaking_exported_api` config option to `false` to enable the `enum_variant_names` lint for public items
+error: lint `clippy::pub_enum_variant_names` has been removed: set the `avoid-breaking-exported-api` config option to `false` to enable the `enum_variant_names` lint for public items
   --> $DIR/deprecated.rs:15:8
    |
 LL | #[warn(clippy::pub_enum_variant_names)]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: lint `clippy::wrong_pub_self_convention` has been removed: set the `avoid_breaking_exported_api` config option to `false` to enable the `wrong_self_convention` lint for public items
+error: lint `clippy::wrong_pub_self_convention` has been removed: set the `avoid-breaking-exported-api` config option to `false` to enable the `wrong_self_convention` lint for public items
   --> $DIR/deprecated.rs:16:8
    |
 LL | #[warn(clippy::wrong_pub_self_convention)]