iwlwifi: mvm: fix harmless smatch / coccinelle warnings

Don't check if mvm->fw->cs is NULL since it can't be.
cs is an array member of iwl_fw, it can't be NULL.

Use memset(ptr, 0, sizeof(*ptr)); instead of
memset(ptr, 0, sizeof(struct ptr_type));

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

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

@@ -262,7 +262,7 @@ int iwl_mvm_mac_setup_register(struct iwl_mvm *mvm)
 	mvm->rts_threshold = IEEE80211_MAX_RTS_THRESHOLD;
 
 	/* currently FW API supports only one optional cipher scheme */
-	if (mvm->fw->cs && mvm->fw->cs->cipher) {
+	if (mvm->fw->cs->cipher) {
 		mvm->hw->n_cipher_schemes = 1;
 		mvm->hw->cipher_schemes = mvm->fw->cs;
 	}

drivers/net/wireless/iwlwifi/mvm/rs.c

@@ -700,7 +700,7 @@ static int rs_rate_from_ucode_rate(const u32 ucode_rate,
 	u8 num_of_ant = get_num_of_ant_from_rate(ucode_rate);
 	u8 nss;
 
-	memset(rate, 0, sizeof(struct rs_rate));
+	memset(rate, 0, sizeof(*rate));
 	rate->index = iwl_hwrate_to_plcp_idx(ucode_rate);
 
 	if (rate->index == IWL_RATE_INVALID) {
@@ -2446,7 +2446,7 @@ static void rs_build_rates_table(struct iwl_mvm *mvm,
 	struct iwl_lq_cmd *lq_cmd = &lq_sta->lq;
 	bool toggle_ant = false;
 
-	memcpy(&rate, initial_rate, sizeof(struct rs_rate));
+	memcpy(&rate, initial_rate, sizeof(rate));
 
 	if (mvm)
 		valid_tx_ant = iwl_fw_valid_tx_ant(mvm->fw);