media: cpia2_usb: fix memory leaks

In submit_urbs(), 'cam->sbuf[i].data' is allocated through kmalloc_array().
However, it is not deallocated if the following allocation for urbs fails.
To fix this issue, free 'cam->sbuf[i].data' if usb_alloc_urb() fails.

Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>