net: mvpp2: Use kmalloc_array() in mvpp2_txq_init()

* A multiplication for the size determination of a memory allocation
  indicated that an array data structure should be processed.
  Thus use the corresponding function "kmalloc_array".

  This issue was detected by using the Coccinelle software.

* Replace the specification of a data structure by a pointer dereference
  to make the corresponding size determination a bit safer according to
  the Linux coding style convention.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvpp2.c

@@ -5083,9 +5083,9 @@ static int mvpp2_txq_init(struct mvpp2_port *port,
 	for_each_present_cpu(cpu) {
 		txq_pcpu = per_cpu_ptr(txq->pcpu, cpu);
 		txq_pcpu->size = txq->size;
-		txq_pcpu->buffs = kmalloc(txq_pcpu->size *
-					  sizeof(struct mvpp2_txq_pcpu_buf),
-					  GFP_KERNEL);
+		txq_pcpu->buffs = kmalloc_array(txq_pcpu->size,
+						sizeof(*txq_pcpu->buffs),
+						GFP_KERNEL);
 		if (!txq_pcpu->buffs)
 			goto error;