[media] usb drivers: use BUG_ON() instead of if () BUG

Some USB drivers have a logic at the VB buffer handling like:
	if (in_interrupt())
		BUG();
Use, instead:
	BUG_ON(in_interrupt());

Btw, this logic looks weird on my eyes. We should convert them
to use VB2, in order to avoid those crappy things.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>