backlight: lp8788: Fully initialize backlight_properties during probe

[ Upstream commit 392346827fbe8a7fd573dfb145170d7949f639a6 ]

props is stack allocated and the fields that are not explcitly set
by the probe function need to be zeroed or we'll get undefined behaviour
(especially so power/blank states)!

Fixes: c5a5105 ("backlight: add new lp8788 backlight driver")
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240220153532.76613-4-daniel.thompson@linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/video/backlight/lp8788_bl.c

@@ -191,6 +191,7 @@ static int lp8788_backlight_register(struct lp8788_bl *bl)
 	int init_brt;
 	char *name;
 
+	memset(&props, 0, sizeof(struct backlight_properties));
 	props.type = BACKLIGHT_PLATFORM;
 	props.max_brightness = MAX_BRIGHTNESS;