perf pmu: zfree() expects a pointer to a pointer to zero it after freeing its contents

stable inclusion
from stable-v5.10.180
commit 604b650fb5742d8a1e654786372473ca3838f2be
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8FC2O

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=604b650fb5742d8a1e654786372473ca3838f2be



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[ Upstream commit 57f14b5a ]

An audit showed just this one problem with zfree(), fix it.

Fixes: 9fbc61f8 ("perf pmu: Add support for PMU capabilities")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>