ipmi: ipmb: Add check devm_kasprintf() returned value

[ Upstream commit 2378bd0b ]

devm_kasprintf() can return a NULL pointer on failure but this
returned value is not checked.

Fixes: 51bd6f29 ("Add support for IPMB driver")
Signed-off-by: Charles Han <hanchunchao@inspur.com>
Message-ID: <20240926094419.25900-1-hanchunchao@inspur.com>
Signed-off-by: Corey Minyard <corey@minyard.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>