Clean the filepath of -ro option.

This fixes problems when using it with a path with trailing slash.

Change-Id: I40abd5379f4d59c2352d95654eb42e11b0949756

cmd/slothfs-populate/main.go

diff --git a/cmd/slothfs-populate/main.go b/cmd/slothfs-populate/main.go
index a336ea7..80101b4 100644
--- a/cmd/slothfs-populate/main.go
+++ b/cmd/slothfs-populate/main.go
@@ -281,6 +281,7 @@
 
 // populateCheckout updates a RW dir with new symlinks to the given RO dir.
 func populateCheckout(ro, rw string) error {
+	ro = filepath.Clean(ro)
 	wsName, err := clearLinks(filepath.Dir(ro), rw)
 	if err != nil {
 		log.Fatal(err)