fix: use var instead of let
fix: use var instead of let

PR-URL: https://github.com/isaacs/rimraf/pull/195
Credit: da39a3ee5e6b4b0d3255bfef95601890afd80709@Tidyzq
Close: #195
Reviewed-by: da39a3ee5e6b4b0d3255bfef95601890afd80709@isaacs

isaacs/rimraf,isaacs/rimraf