i40iw: Protect req_resource_num update

commit 44856be3 upstream.

In i40iw_alloc_resource(), ensure that the update to
req_resource_num is protected by the lock.

Fixes: 8e06af71 ("i40iw: add main, hdr, status")
Reported-by: Stefan Assmann <sassmann@redhat.com>
Signed-off-by: Mustafa Ismail <mustafa.ismail@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/infiniband/hw/i40iw/i40iw.h

@@ -435,8 +435,8 @@ static inline int i40iw_alloc_resource(struct i40iw_device *iwdev,
 	*next = resource_num + 1;
 	if (*next == max_resources)
 		*next = 0;
-	spin_unlock_irqrestore(&iwdev->resource_lock, flags);
 	*req_resource_num = resource_num;
+	spin_unlock_irqrestore(&iwdev->resource_lock, flags);
 
 	return 0;
 }