[PATCH] ipw2200: Fix qos_cmd param switch bug

The patch fixes a couple of errors regarding QoS, which results in
compile warnings and malfunction of the driver.

Signed-off-by: Henrik Brix Andersen <brix@gentoo.org>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>