admin: do_list do not shadow local variables

Remove second declaration of 's' which shadows an existing variable.

Change-Id: I2277663ab051fb4ed10823fb43489cee06bb502b

admin/list.c

@@ -129,7 +129,6 @@ do_list(struct list_options *opt, const char *keytab_str)
 	if (entry.aliases) {
 	    unsigned int i;
 	    struct rk_strpool *p = NULL;
-            char *s;
 
 	    for (i = 0; i< entry.aliases->len; i++) {
 		krb5_unparse_name_fixed(context, entry.principal, buf, sizeof(buf));