It seems that the return value of usb_ifnum_to_if() can be NULL and
needs to be checked.
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Tested-by: NAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: NSean Young <sean@mess.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>