style: clean use for question_mark

- remove useless `Ok` enclosing with `?`
lint message: enclosing `Ok` and `?` operator are unneeded
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#needless_question_mark
- use question mark instead of manual implementation
lint message: this `match` expression can be replaced with `?`
help: for further information visit https://rust-lang.github.io/rust-clippy/rust-1.92.0/index.html#question_mark

src/db/fjall_adapter.rs

@@ -105,12 +105,11 @@ impl IDb for FjallDb {
 	}
 
 	fn list_trees(&self) -> Result<Vec<String>> {
-		Ok(self
-			.keyspace
+		self.keyspace
 			.list_partitions()
 			.iter()
 			.map(|n| decode_name(n))
-			.collect::<Result<Vec<_>>>()?)
+			.collect::<Result<Vec<_>>>()
 	}
 
 	fn snapshot(&self, base_path: &Path) -> Result<()> {