Remove uses of Error::description() use Display instead (#2887)

* Remove all uses of Error::description() - use Display instead

substrate/core/client/db/src/utils.rs

@@ -190,7 +190,7 @@ pub fn block_id_to_lookup_key<Block>(
 /// Maps database error to client error
 pub fn db_err(err: io::Error) -> client::error::Error {
 	use std::error::Error;
-	client::error::Error::Backend(err.description().into())
+	client::error::Error::Backend(format!("{}", err))
 }
 
 /// Open RocksDB database.