commit 5f0163a5 upstream.

The put_device() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[wt: backported only to ease next patch as suggested by Jiri]
Signed-off-by: Willy Tarreau <w@1wt.eu>