media: imx: vdic: Restore default case to prepare_vdi_in_buffers()

Restore a default case to prepare_vdi_in_buffers() to fix the following
smatch errors:

drivers/staging/media/imx/imx-media-vdic.c:236 prepare_vdi_in_buffers() error: uninitialized symbol 'prev_phys'.
drivers/staging/media/imx/imx-media-vdic.c:237 prepare_vdi_in_buffers() error: uninitialized symbol 'curr_phys'.
drivers/staging/media/imx/imx-media-vdic.c:238 prepare_vdi_in_buffers() error: uninitialized symbol 'next_phys'.

Fixes: 6e537b58 ("media: imx: vdic: rely on VDIC for correct field order")
Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/staging/media/imx/imx-media-vdic.c

@@ -231,6 +231,12 @@ static void __maybe_unused prepare_vdi_in_buffers(struct vdic_priv *priv,
 		curr_phys = vb2_dma_contig_plane_dma_addr(curr_vb, 0);
 		next_phys = vb2_dma_contig_plane_dma_addr(curr_vb, 0) + is;
 		break;
+	default:
+		/*
+		 * can't get here, priv->fieldtype can only be one of
+		 * the above. This is to quiet smatch errors.
+		 */
+		return;
 	}
 
 	ipu_cpmem_set_buffer(priv->vdi_in_ch_p, 0, prev_phys);