chelsio: Fix non-NAPI compile

Chelsio without NAPI enabled has been broken (won't compile) since
3de00b89

 ("chelsio: NAPI speed improvement"):

    drivers/net/chelsio/sge.c: In function `t1_interrupt`:
    drivers/net/chelsio/sge.c:1716: error: `Q` undeclared (first use in this function)

The change below seems to add back in the declaration and
initialization of `Q` that was removed by mistake, and at least makes
the driver compile for me, although I have no hardware and hence no
way to test whether this actually works.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>