drm: xlnx: zynqmp_disp: layer may be null while releasing

layer->info can be null if we have an error on the first layer in
zynqmp_disp_create_layers

Fixes: 1836fd5 ("drm: xlnx: zynqmp_dpsub: Minimize usage of global flag")
Signed-off-by: Steffen Dirkwinkel <[email protected]>
Signed-off-by: Tomi Valkeinen <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: sdirkwinkel

drivers/gpu/drm/xlnx/zynqmp_disp.c

@@ -1200,6 +1200,9 @@ static void zynqmp_disp_layer_release_dma(struct zynqmp_disp *disp,
 {
 	unsigned int i;
 
+	if (!layer->info)
+		return;
+
 	for (i = 0; i < layer->info->num_channels; i++) {
 		struct zynqmp_disp_layer_dma *dma = &layer->dmas[i];