cifs: fix use after free for iface while disabling secondary channels

We were deferencing iface after it has been released. Fix is to
release after all dereference instances have been encountered.

Signed-off-by: Ritvik Budhiraja <rbudhiraja@microsoft.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/202311110815.UJaeU3Tt-lkp@intel.com/
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: ritbudhiraja

fs/smb/client/sess.c

@@ -332,10 +332,10 @@ cifs_disable_secondary_channels(struct cifs_ses *ses)
 
 		if (iface) {
 			spin_lock(&ses->iface_lock);
-			kref_put(&iface->refcount, release_iface);
 			iface->num_channels--;
 			if (iface->weight_fulfilled)
 				iface->weight_fulfilled--;
+			kref_put(&iface->refcount, release_iface);
 			spin_unlock(&ses->iface_lock);
 		}