Cleanup usage of global logger (#26835)

server/channels/app/platform/session.go

@@ -235,7 +235,7 @@ func (ps *PlatformService) UpdateSessionsIsGuest(c request.CTX, user *model.User
 		session.AddProp(model.SessionPropIsGuest, strconv.FormatBool(isGuest))
 		err := ps.Store.Session().UpdateProps(session)
 		if err != nil {
-			mlog.Warn("Unable to update isGuest session", mlog.Err(err))
+			c.Logger().Warn("Unable to update isGuest session", mlog.Err(err))
 			continue
 		}
 		ps.AddSessionToCache(session)