mac80211: free peer keys before vif down in mesh

[ Upstream commit 0112fa55 ]

freeing peer keys after vif down is resulting in peer key uninstall
to fail due to interface lookup failure. so fix that.

Signed-off-by: Pradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>