[ Upstream commit 03dd0d49de7db680a856fa566963bb8421f46368 ] Make sure the nss is valid for nss_delta array. Return zero if the index is invalid. Coverity message: Event overrun-call: Overrunning callee's array of size 4 by passing argument "n_chains" (which evaluates to 15) in call to "mt76_tx_power_nss_delta". int delta = mt76_tx_power_nss_delta(n_chains); Fixes: 07cda406308b ("mt76: fix rounding issues on converting per-chain and combined txpower") Signed-off-by: Deren Wu <deren.wu@mediatek.com> Signed-off-by: Felix Fietkau <nbd@nbd.name> Signed-off-by: Sasha Levin <sashal@kernel.org>