iwlwifi: increase scan timeout

When the first interface is active, then scanning
on it or the second interface can take a little
longer than 7s (I observed around 8s.) Bump the
timeout to 15s to avoid aborting a scan that is
still running, just taking more time.
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/iwlwifi/dvm/agn.h

@@ -269,7 +269,7 @@ void iwl_scan_offchannel_skb_status(struct iwl_priv *priv);
 #define IWL_ACTIVE_QUIET_TIME       cpu_to_le16(10)  /* msec */
 #define IWL_PLCP_QUIET_THRESH       cpu_to_le16(1)  /* packets */
 
-#define IWL_SCAN_CHECK_WATCHDOG		(HZ * 7)
+#define IWL_SCAN_CHECK_WATCHDOG		(HZ * 15)
 
 
 /* bt coex */