V4L/DVB (13154): uvcvideo: Handle garbage at the end of streaming interface descriptors

At least one 5986:0241 webcam model includes vendor-specific descriptors
at the end of its streaming interface descriptors. Print an information
UVC_TRACE_DESCR message and try to continue parsing the descriptors
rather than bailing out with an error.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>