drivers/net/typhoon.c: delete double assignment

Delete successive assignments to the same location.  The current definition
does not initialize the respRing structure, which has the same type as the
cmdRing structure, so initialize that one instead.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/

)

// <smpl>
@@
expression i;
@@

*i = ...;
 i = ...;
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: David Dillow <dave@thedillows.org>
Signed-off-by: David S. Miller <davem@davemloft.net>