iwlwifi: enable serialization of synchronous commands

Until now it was only possible to have one synchronous command running at
any time. If a synchronous command is in progress when a second request
arrives then the second command will fail. Create a new mutex specific for
this purpose to only allow one synchronous command at a time, but enable
other commands to wait instead of fail if a synchronous command is in
progress.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-core.h b/drivers/net/wireless/iwlwifi/iwl-core.h
index 530fae8..6347d4b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.h
+++ b/drivers/net/wireless/iwlwifi/iwl-core.h
@@ -603,7 +603,7 @@
 /*************** DRIVER STATUS FUNCTIONS   *****/
 
 #define STATUS_HCMD_ACTIVE	0	/* host command in progress */
-#define STATUS_HCMD_SYNC_ACTIVE	1	/* sync host command in progress */
+/* 1 is unused (used to be STATUS_HCMD_SYNC_ACTIVE) */
 #define STATUS_INT_ENABLED	2
 #define STATUS_RF_KILL_HW	3
 #define STATUS_CT_KILL		4