fs: remove unnecessary else statement

PR-URL: #32662
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>

lib/internal/fs/promises.js

@@ -188,11 +188,8 @@ async function readFileHandle(filehandle, options) {
   } while (!endOfFile);
 
   const result = Buffer.concat(chunks);
-  if (options.encoding) {
-    return result.toString(options.encoding);
-  } else {
-    return result;
-  }
+
+  return options.encoding ? result.toString(options.encoding) : result;
 }
 
 // All of the functions are defined as async in order to ensure that errors