mac80211: call drv_stop only if driver is started

If drv_start() fails during hw_restart, all the running
interfaces are being closed/stopped, which results in
drv_stop() being called, although the driver was never
started successfully.

This might cause drivers to perform operations on uninitialized
memory (as they assume it was initialized on drv_start)

Consider the local->started flag, and call the driver's stop()
op only if drv_start() succeeded before.

Move drv_start() and drv_stop() to driver-ops.c, as they are no
longer simple wrappers.

Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index b0e3a42..551164d 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1665,7 +1665,6 @@
 
 	local->resuming = false;
 	local->suspended = false;
-	local->started = false;
 	local->in_reconfig = false;
 
 	/* scheduled scan clearly can't be running any more, but tell
@@ -1764,6 +1763,8 @@
 	if (suspended && local->in_reconfig && !reconfig_due_to_wowlan)
 		cancel_work_sync(&local->restart_work);
 
+	local->started = false;
+
 	/*
 	 * Upon resume hardware can sometimes be goofy due to
 	 * various platform / driver / bus issues, so restarting