[ Upstream commit 1a473d60 ]

The bits of Rx MCS Map in VHT capability were enumerated
with index transform - index i -> (i + 1) bit => nss i. BUG!
while it should be -   index i -> (i + 1) bit => (i + 1) nss.

The bug was exposed in commit a53b2a0b ("iwlwifi: mvm: implement VHT
extended NSS support in rs.c"), where iwlwifi started using the
function.
Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Fixes: b0aa75f0 ("ieee80211: add new VHT capability fields/parsing")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>