drm/komeda: Fix error: not allocating enough data 1592 vs 1584

The patch 5d51f6c0da1b: "drm/komeda: Add writeback support" from May
23, 2019, leads to the following static checker warning:

drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c:151 komeda_wb_connector_add()
error: not allocating enough data 1592 vs 1584

This is a typo which misuse "wb_conn" but which should be "kwb_conn" to
allocate the memory.

Reported-by: Dan Carpenter <[e-mail]>
Signed-off-by: james qian wang (Arm Technology China) <[e-mail]>
Reviewed-by: Ayan Kumar Halder <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/arm/display/komeda/komeda_wb_connector.c

···
 	if (!kcrtc->master->wb_layer)
 		return 0;
 
-	kwb_conn = kzalloc(sizeof(*wb_conn), GFP_KERNEL);
+	kwb_conn = kzalloc(sizeof(*kwb_conn), GFP_KERNEL);
 	if (!kwb_conn)
 		return -ENOMEM;