Fix collectFile saving to GCS with sort: false (#4965)

Signed-off-by: Ben Sherman <[email protected]>

modules/nextflow/src/main/groovy/nextflow/file/SimpleFileCollector.groovy

@@ -15,14 +15,15 @@
  */
 
 package nextflow.file
+
 import java.nio.file.Files
 import java.nio.file.Path
-import java.nio.file.StandardCopyOption
 import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.ConcurrentMap
 
 import groovy.transform.CompileStatic
 import groovy.util.logging.Slf4j
+import nextflow.extension.FilesEx
 /**
  *  Helper class used to aggregate values having the same key
  *  to files
@@ -94,16 +95,13 @@ class SimpleFileCollector extends FileCollector {
     @Override
     void saveFile( Closure<Path> closure ) {
 
-        def result = []
         Iterator<Path> itr = cache.values().iterator()
         while( itr.hasNext() ) {
-            def item = itr.next()
-            def target = closure.call(item.getName())
-            result << Files.move(item, target, StandardCopyOption.REPLACE_EXISTING)
+            final item = itr.next()
+            final target = closure.call(item.getName())
+            FilesEx.moveTo(item, target)
             itr.remove()
         }
-
     }
 
-
 }