[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>

drivers/media/usb/zr364xx/zr364xx.c

@@ -377,8 +377,7 @@ static void free_buffer(struct videobuf_queue *vq, struct zr364xx_buffer *buf)
 {
 	_DBG("%s\n", __func__);
 
-	if (in_interrupt())
-		BUG();
+	BUG_ON(in_interrupt());
 
 	videobuf_vmalloc_free(&buf->vb);
 	buf->vb.state = VIDEOBUF_NEEDS_INIT;