Make config_item_type structures const as they are either passed to a
function having the argument as const or used inside an if statement or
stored in the const "ci_type" field of a config_item structure.

Done using Coccinelle
Signed-off-by: NBhumika Goyal <bhumirks@gmail.com>
Acked-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>