mtd: devices: docg3: check the return value of devm_ioremap() in the probe

mtd: devices: docg3: check the return value of devm_ioremap() in the probe

[ Upstream commit 26e784433e6c65735cd6d93a8db52531970d9a60 ]

The function devm_ioremap() in docg3_probe() can fail, so
its return value should be checked.

Fixes: 82402aeb8c81e ("mtd: docg3: Use devm_*() functions")
Reported-by: Hacash Robot <hacashRobot@santino.com>
Signed-off-by: William Dean <williamsukatube@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220722091644.2937953-1-williamsukatube@163.com
Signed-off-by: Sasha Levin <sashal@kernel.org>