leds: lp5523: fix a missing check of return value of lp55xx_read

BugLink: https://bugs.launchpad.net/bugs/1822271

[ Upstream commit 248b5701 ]

When lp55xx_read() fails, "status" is an uninitialized variable and thus
may contain random value; using it leads to undefined behaviors.

The fix inserts a check for the return value of lp55xx_read: if it
fails, returns with its error code.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/leds/leds-lp5523.c

@@ -318,7 +318,9 @@ static int lp5523_init_program_engine(struct lp55xx_chip *chip)
 
 	/* Let the programs run for couple of ms and check the engine status */
 	usleep_range(3000, 6000);
-	lp55xx_read(chip, LP5523_REG_STATUS, &status);
+	ret = lp55xx_read(chip, LP5523_REG_STATUS, &status);
+	if (ret)
+		return ret;
 	status &= LP5523_ENG_STATUS_MASK;
 
 	if (status != LP5523_ENG_STATUS_MASK) {