selftests/resctrl: Return NULL if malloc_and_init_memory() did not alloc mem

stable inclusion
from stable-v5.10.180
commit 4075fbcde40f2e12130964abedfb418469238af1
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8DDFN

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4075fbcde40f2e12130964abedfb418469238af1



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[ Upstream commit 22a8be28 ]

malloc_and_init_memory() in fill_buf isn't checking if memalign()
successfully allocated memory or not before accessing the memory.

Check the return value of memalign() and return NULL if allocating
aligned memory fails.

Fixes: a2561b12 ("selftests/resctrl: Add built in benchmark")
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>