all: Simplify some method calls (#7499)

strings.Replace(a, b, c, -1) -> strings.ReplaceAll(a, b, c)

(Go 1.12) and who knows what was up with that dialQueue.Sort() thing.

lib/fs/filesystem.go

@@ -252,8 +252,7 @@ func Canonicalize(file string) (string, error) {
 	file = filepath.Clean(file)
 
 	// It is not acceptable to attempt to traverse upwards.
-	switch file {
-	case "..":
+	if file == ".." {
 		return "", errNotRelative
 	}
 	if strings.HasPrefix(file, ".."+pathSep) {