correct wrong doc syntax

clippy_lints/src/manual_is_ascii_check.rs

@@ -74,7 +74,7 @@ enum CharRange {
     LowerChar,
     /// 'A'..='Z' | b'A'..=b'Z'
     UpperChar,
-    /// AsciiLower | AsciiUpper
+    /// `AsciiLower` | `AsciiUpper`
     FullChar,
     /// '0..=9'
     Digit,

clippy_lints/src/methods/filter_map.rs

@@ -75,7 +75,7 @@ enum OffendingFilterExpr<'tcx> {
     },
     /// `.filter(|enum| matches!(enum, Enum::A(_)))`
     Matches {
-        /// The DefId of the variant being matched
+        /// The `DefId` of the variant being matched
         variant_def_id: hir::def_id::DefId,
     },
 }

clippy_lints/src/question_mark.rs

@@ -74,12 +74,12 @@ impl QuestionMark {
 enum IfBlockType<'hir> {
     /// An `if x.is_xxx() { a } else { b } ` expression.
     ///
-    /// Contains: caller (x), caller_type, call_sym (is_xxx), if_then (a), if_else (b)
+    /// Contains: `caller (x), caller_type, call_sym (is_xxx), if_then (a), if_else (b)`
     IfIs(&'hir Expr<'hir>, Ty<'hir>, Symbol, &'hir Expr<'hir>),
     /// An `if let Xxx(a) = b { c } else { d }` expression.
     ///
-    /// Contains: let_pat_qpath (Xxx), let_pat_type, let_pat_sym (a), let_expr (b), if_then (c),
-    /// if_else (d)
+    /// Contains: `let_pat_qpath (Xxx), let_pat_type, let_pat_sym (a), let_expr (b), if_then (c),
+    /// if_else (d)`
     IfLet(
         Res,
         Ty<'hir>,

clippy_lints/src/slow_vector_initialization.rs

@@ -62,7 +62,7 @@ declare_lint_pass!(SlowVectorInit => [SLOW_VECTOR_INITIALIZATION]);
 /// assigned to a variable. For example, `let mut vec = Vec::with_capacity(0)` or
 /// `vec = Vec::with_capacity(0)`
 struct VecAllocation<'tcx> {
-    /// HirId of the variable
+    /// `HirId` of the variable
     local_id: HirId,
 
     /// Reference to the expression which allocates the vector