check: fix --one-way recursing more directories than it needs to

Before this change rclone traversed all directories in the destination.

After this change rclone doesn't traverse directories in the
destination that don't exist in the source if the `--one-way` flag is
set.

See: https://forum.rclone.org/t/check-with-one-way-flag-should-not-traverses-all-destination-directories/13263

Author: ncw

fs/operations/operations.go

@@ -721,6 +721,9 @@ func (c *checkMarch) DstOnly(dst fs.DirEntry) (recurse bool) {
 		atomic.AddInt32(&c.srcFilesMissing, 1)
 	case fs.Directory:
 		// Do the same thing to the entire contents of the directory
+		if c.oneway {
+			return false
+		}
 		return true
 	default:
 		panic("Bad object in DirEntries")