Make the code read easier

Sources/SwiftUI/ImageBinder.swift

@@ -79,10 +79,8 @@ extension KFImage {
                         switch result {
                         case .success(let value):
                             CallbackQueue.mainCurrentOrAsync.execute {
-                                if let animation = (context
-                                    .fadeTransitionDuration(cacheType: value.cacheType)
-                                    .map { duration in Animation.linear(duration: duration) })
-                                {
+                                if let fadeDuration = context.fadeTransitionDuration(cacheType: value.cacheType) {
+                                    let animation = Animation.linear(duration: fadeDuration)
                                     withAnimation(animation) { self.loaded = true }
                                 } else {
                                     self.loaded = true