Simplify os.ModeType|os.ModeCharDevice => os.ModeType

Since Go 1.12, ModeCharDevice is included in ModeType:
golang/go@a2a3dd00c9

internal/fs/helpers.go

@@ -9,5 +9,5 @@ func IsRegularFile(fi os.FileInfo) bool {
 		return false
 	}
 
-	return fi.Mode()&(os.ModeType|os.ModeCharDevice) == 0
+	return fi.Mode()&os.ModeType == 0
 }