drm/rockchip: vop: report error when check resource error

The user would be confused while facing a error commit without
any error report.

Signed-off-by: Mark Yao <mark.yao@rock-chips.com>
Reviewed-by: Sandy huang <sandy.huang@rock-chips.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1501494596-7090-1-git-send-email-mark.yao@rock-chips.com