fix(xfunc ssh identityfile): localize change to cur

Author: akinomyoga

completions/ssh

@@ -274,6 +274,7 @@ _comp_cmd_ssh__configfile()
 # shellcheck disable=SC2120
 _comp_xfunc_ssh_identityfile()
 {
+    local cur=$cur
     [[ ! $cur && -d ~/.ssh ]] && cur=~/.ssh/id
     _comp_compgen -a filedir
     if ((${#COMPREPLY[@]} > 0)); then