drm: mali-dp: potential dereference of null pointer

mainline inclusion
from mainline-v5.19-rc1
commit 73c3ed74
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I6698V
CVE: CVE-2022-3115

--------------------------------

The return value of kzalloc() needs to be checked.
To avoid use of null pointer '&state->base' in case of the
failure of alloc.

Fixes: 99665d07 ("drm: mali-dp: add malidp_crtc_state struct")
Signed-off-by: NJiasheng Jiang <jiasheng@iscas.ac.cn>
Reviewed-by: NBrian Starkey <brian.starkey@arm.com>
Signed-off-by: NLiviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211214100837.46912-1-jiasheng@iscas.ac.cn

Conflicts:
	drivers/gpu/drm/arm/malidp_crtc.c
Signed-off-by: NChenXiaoSong <chenxiaosong2@huawei.com>
Reviewed-by: NZhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: NXiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

drivers/gpu/drm/arm/malidp_crtc.c

@@ -473,6 +473,8 @@ static void malidp_crtc_reset(struct drm_crtc *crtc)
 	if (state) {
 		crtc->state = &state->base;
 		crtc->state->crtc = crtc;
+	} else {
+		crtc->state = NULL;
 	}
 }