media: videobuf2: remove unused variable

Commit 2cc1802f ("media: vb2: Keep dma-buf buffers mapped until
they are freed") removed code leaving a local variable unused.

Remove it to avoid a compiler warning.

Fixes: 2cc1802f ("media: vb2: Keep dma-buf buffers mapped until they are freed")
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/common/videobuf2/videobuf2-core.c

@@ -1769,7 +1769,6 @@ EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
 static void __vb2_dqbuf(struct vb2_buffer *vb)
 {
 	struct vb2_queue *q = vb->vb2_queue;
-	unsigned int i;
 
 	/* nothing to do if the buffer is already dequeued */
 	if (vb->state == VB2_BUF_STATE_DEQUEUED)