[ Upstream commit b55d073e6501dc6077edaa945a6dad8ac5c8bbab ] smatch complains that there is a buffer overflow and clang complains 'ret' is never read. Smatch error: drivers/power/supply/bq256xx_charger.c:1578 bq256xx_hw_init() error: buffer overflow 'bq256xx_watchdog_time' 4 <= 4 Clang static checker: Value stored to 'ret' is never read. Add check for buffer overflow and error code from regmap_update_bits(). Fixes: 32e4978bb920 ("power: supply: bq256xx: Introduce the BQ256XX charger driver") Signed-off-by: Su Hui <suhui@nfschina.com> Link: https://lore.kernel.org/r/20231116041822.1378758-1-suhui@nfschina.com Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> Signed-off-by: Sasha Levin <sashal@kernel.org>