Fix SwiftLint violation

Sources/Yams/Constructor.swift

@@ -441,7 +441,6 @@ extension Array {
         return sequence.map(sequence.tag.constructor.any)
     }
 
-
     /// Construct an "O-map" (array of `(Any, Any)` tuples) from the specified `sequence`.
     ///
     /// - parameter sequence: Sequence to convert to `Array<(Any, Any)>`.

Sources/Yams/Node.Mapping.swift

@@ -155,8 +155,7 @@ extension Node.Mapping {
     /// Set or get the specified `Node`.
     public subscript(node: Node) -> Node? {
         get {
-            let v = pairs.reversed().first(where: { $0.key == node })
-            return v?.value
+            return pairs.reversed().first(where: { $0.key == node })?.value
         }
         set {
             if let newValue = newValue {