usbip: remove unneeded structure

Delete a local structure that is only used to be initialized by memset.

A semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/

)

// <smpl>
@@
identifier x,i;
@@

{
... when any
-struct i x;
<+... when != x
- memset(&x,...);
...+>
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Valentina Manea <valentina.manea.m@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>