media: iguanair: fix endpoint sanity check

media: iguanair: fix endpoint sanity check

[ Upstream commit 1b257870a78b0a9ce98fdfb052c58542022ffb5b ]

Make sure to use the current alternate setting, which need not be the
first one by index, when verifying the endpoint descriptors and
initialising the URBs.

Failing to do so could cause the driver to misbehave or trigger a WARN()
in usb_submit_urb() that kernels with panic_on_warn set would choke on.

Fixes: 26ff63137c45 ("[media] Add support for the IguanaWorks USB IR Transceiver")
Fixes: ab1cbdf159be ("media: iguanair: add sanity checks")
Cc: stable <stable@vger.kernel.org>     # 3.6
Cc: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>