Remove unneeded From trait impl for DefKind

Author: GuillaumeGomez

src/librustdoc/clean/mod.rs

@@ -1042,7 +1042,7 @@ impl Clean<PolyTrait> for hir::PolyTraitRef<'_> {
 
 impl Clean<TypeKind> for hir::def::DefKind {
     fn clean(&self, _: &DocContext<'_>) -> TypeKind {
-        self.into()
+        (*self).into()
     }
 }
 

src/librustdoc/clean/types.rs

@@ -1302,12 +1302,6 @@ crate enum TypeKind {
     Primitive,
 }
 
-impl<'a> From<&'a hir::def::DefKind> for TypeKind {
-    fn from(other: &hir::def::DefKind) -> Self {
-        Self::from(*other)
-    }
-}
-
 impl From<hir::def::DefKind> for TypeKind {
     fn from(other: hir::def::DefKind) -> Self {
         match other {