iwlwifi: mvm: Don't install CMAC/GMAC key in AP mode

Due to a missing break, the management multicast key was installed even
though we don't really support it. Fix that, so mac80211 would know that
it should protect frames in software.
Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200926002540.019a64e96d44.I609a995611ac5286e442cd54f764eaf4a7249ac0@changeidSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c

@@ -3438,15 +3438,16 @@ static int __iwl_mvm_mac_set_key(struct ieee80211_hw *hw,
 			 */
 			if (key->cipher == WLAN_CIPHER_SUITE_AES_CMAC ||
 			    key->cipher == WLAN_CIPHER_SUITE_BIP_GMAC_128 ||
-			    key->cipher == WLAN_CIPHER_SUITE_BIP_GMAC_256)
+			    key->cipher == WLAN_CIPHER_SUITE_BIP_GMAC_256) {
 				ret = -EOPNOTSUPP;
-			else
-				ret = 0;
+				break;
+			}
 
 			if (key->cipher != WLAN_CIPHER_SUITE_GCMP &&
 			    key->cipher != WLAN_CIPHER_SUITE_GCMP_256 &&
 			    !iwl_mvm_has_new_tx_api(mvm)) {
 				key->hw_key_idx = STA_KEY_IDX_INVALID;
+				ret = 0;
 				break;
 			}
 
@@ -3462,6 +3463,8 @@ static int __iwl_mvm_mac_set_key(struct ieee80211_hw *hw,
 
 				if (i >= ARRAY_SIZE(mvmvif->ap_early_keys))
 					ret = -ENOSPC;
+				else
+					ret = 0;
 
 				break;
 			}