iwlagn: use kcalloc when possible for array allocation

As everybody knows kcalloc checks the multiplication is safe and
that we don't run into overflow.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
index 781f6aa..416e992 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c
@@ -304,8 +304,8 @@
 
 	txq->q.n_window = slots_num;
 
-	txq->meta = kzalloc(sizeof(txq->meta[0]) * slots_num, GFP_KERNEL);
-	txq->cmd = kzalloc(sizeof(txq->cmd[0]) * slots_num, GFP_KERNEL);
+	txq->meta = kcalloc(slots_num, sizeof(txq->meta[0]), GFP_KERNEL);
+	txq->cmd = kcalloc(slots_num, sizeof(txq->cmd[0]), GFP_KERNEL);
 
 	if (!txq->meta || !txq->cmd)
 		goto error;
@@ -322,8 +322,8 @@
 	/* Driver private data, only for Tx (not command) queues,
 	 * not shared with device. */
 	if (txq_id != trans->shrd->cmd_queue) {
-		txq->skbs = kzalloc(sizeof(txq->skbs[0]) *
-				   TFD_QUEUE_SIZE_MAX, GFP_KERNEL);
+		txq->skbs = kcalloc(TFD_QUEUE_SIZE_MAX, sizeof(txq->skbs[0]),
+				    GFP_KERNEL);
 		if (!txq->skbs) {
 			IWL_ERR(trans, "kmalloc for auxiliary BD "
 				  "structures failed\n");
@@ -534,8 +534,8 @@
 		goto error;
 	}
 
-	trans_pcie->txq = kzalloc(sizeof(struct iwl_tx_queue) *
-			hw_params(trans).max_txq_num, GFP_KERNEL);
+	trans_pcie->txq = kcalloc(hw_params(trans).max_txq_num,
+				  sizeof(struct iwl_tx_queue), GFP_KERNEL);
 	if (!trans_pcie->txq) {
 		IWL_ERR(trans, "Not enough memory for txq\n");
 		ret = ENOMEM;