Revert "lib/model: Handle filename conflicts on Windows."

This reverts commit 01e50eb3fa.

lib/scanner/walk.go

@@ -130,14 +130,6 @@ func (w *walker) walk() (chan protocol.FileInfo, error) {
 			filepath.Walk(w.Dir, hashFiles)
 		} else {
 			for _, sub := range w.Subs {
-				if !osutil.IsDir(w.Dir, filepath.Dir(sub)) {
-					l.Infoln("Skipping sub path that is not in a directory", w.Dir, sub)
-					continue
-				}
-				if !osutil.CheckNameConflict(w.Dir, sub) {
-					l.Infoln("Skipping sub path that collides", w.Dir, sub)
-					continue
-				}
 				filepath.Walk(filepath.Join(w.Dir, sub), hashFiles)
 			}
 		}