rgw admin: add tenant argument to reshard cancel

Looks like we ignore the tenant argument for reshard cancel as mentioned in the
issue.

Fixes: https://tracker.ceph.com/issues/38214
Reported-by: Ed Fisher <ed@debacle.org>
Signed-off-by: Abhishek Lekshmanan <abhishek@suse.com>
(cherry picked from commit ff64af3)

src/rgw/rgw_admin.cc

@@ -6269,7 +6269,7 @@ int main(int argc, const char **argv)
     RGWReshard reshard(store);
 
     cls_rgw_reshard_entry entry;
-    //entry.tenant = tenant;
+    entry.tenant = tenant;
     entry.bucket_name = bucket_name;
     //entry.bucket_id = bucket_id;