Fix comments from review feedback

crates/matrix-sdk-base/src/rooms/normal.rs

@@ -85,11 +85,13 @@ pub enum RoomState {
 
 impl From<&MembershipState> for RoomState {
     fn from(membership_state: &MembershipState) -> Self {
+        // We consider Ban, Knock and Leave to be Left, because they all mean we are not
+        // in the room.
         match membership_state {
-            MembershipState::Ban => Self::Left, // TODO: is this right?
+            MembershipState::Ban => Self::Left,
             MembershipState::Invite => Self::Invited,
             MembershipState::Join => Self::Joined,
-            MembershipState::Knock => Self::Left, // TODO: is this right?
+            MembershipState::Knock => Self::Left,
             MembershipState::Leave => Self::Left,
             _ => panic!("Unexpected MembershipState: {}", membership_state),
         }

crates/matrix-sdk-base/src/sliding_sync.rs

@@ -497,7 +497,7 @@ mod test {
         set_room_left(&mut room, user_id);
         let response = response_with_room(room_id, room).await;
         client.process_sliding_sync(&response).await.expect("Failed to process sync");
-        // (sanity: state is invite)
+        // (sanity: state is left)
         assert_eq!(client.get_room(room_id).unwrap().state(), RoomState::Left);
 
         // And then get invited back