iwlagn: fix minimum number of queues setting

We need to provide a reasonable minimum that will result in a
working setup if used. Set minimum to be 10 to provide for
4 standard TX queues + 1 command queue + 2 (unused) HCCA queues +
4 HT queues (one per AC).

We allow the user to change the number of queues used via a module
parameter and use this minimum value to check if it is valid. Without
this patch a user can select a value for the number of queues that
will result in a failing setup.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Tomas Winkler <tomas.winkler@intel.com>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-dev.h

@@ -258,8 +258,10 @@ struct iwl_channel_info {
 #define IWL_TX_FIFO_HCCA_2	6
 #define IWL_TX_FIFO_NONE	7
 
-/* Minimum number of queues. MAX_NUM is defined in hw specific files */
-#define IWL_MIN_NUM_QUEUES	4
+/* Minimum number of queues. MAX_NUM is defined in hw specific files.
+ * Set the minimum to accommodate the 4 standard TX queues, 1 command
+ * queue, 2 (unused) HCCA queues, and 4 HT queues (one for each AC) */
+#define IWL_MIN_NUM_QUEUES	10
 
 /* Power management (not Tx power) structures */