mac80211: rx: avoid RCU list traversal under mutex

mac80211: rx: avoid RCU list traversal under mutex

BugLink: https://bugs.launchpad.net/bugs/1869732
[ Upstream commit 253216ffb2a002a682c6f68bd3adff5b98b71de8 ]

local->sta_mtx is held in __ieee80211_check_fast_rx_iface().
No need to use list_for_each_entry_rcu() as it also requires
a cond argument to avoid false lockdep warnings when not used in
RCU read-side section (with CONFIG_PROVE_RCU_LIST).
Therefore use list_for_each_entry();

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Link: https://lore.kernel.org/r/20200223143302.15390-1-madhuparnabhowmik10@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>