Remove orphaned comment from _get_group_details

This is a follow up to change
I745aecb008f0867fcda2d3d2c7691621dd8f6168 which
removed the code for which the comment was related
and is now orphaned. This change removes the comment
since it has no context/relevance to the code around
it now.

Change-Id: I554ab5552df9b83fcdcc9d530ccb0e54081f4ed7

Author: mriedem

nova/scheduler/utils.py

@@ -939,8 +939,6 @@ def _get_group_details(context, instance_uuid, user_group_hosts=None):
             msg = _("ServerGroupSoftAntiAffinityWeigher not configured")
             LOG.error(msg)
             raise exception.UnsupportedPolicyException(reason=msg)
-        # NOTE(melwitt): If the context is already targeted to a cell (during a
-        # move operation), we don't need to scatter-gather.
         group_hosts = set(group.get_hosts())
         user_hosts = set(user_group_hosts) if user_group_hosts else set()
         return GroupDetails(hosts=user_hosts | group_hosts,