drivers/net/r6040.c: Eliminate double sizeof

Taking sizeof the result of sizeof is quite strange and does not seem to be
what is wanted here.

This was fixed using the following semantic patch.
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression E;
@@

- sizeof (
  sizeof (E)
- )
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

drivers/net/r6040.c

@@ -273,7 +273,7 @@ static void r6040_init_ring_desc(struct r6040_descriptor *desc_ring,
 	dma_addr_t mapping = desc_dma;
 
 	while (size-- > 0) {
-		mapping += sizeof(sizeof(*desc));
+		mapping += sizeof(*desc);
 		desc->ndesc = cpu_to_le32(mapping);
 		desc->vndescp = desc + 1;
 		desc++;