KernelApiSysfsTest: make per-CPU cpufreq nodes optional

CPU hotplug may race with the testing of per-CPU cpufreq nodes. If the
test is unable to read the permissions or contents of a per-CPU cpufreq
file skip the check. Otherwise proceed with verifying the permissions
and/or contents.

Bug: 117797706
Bug: 117628195
Test: run vts-kernel -m VtsKernelApiSysfs
Change-Id: Id31f2159eaff6f6c018cc6b7b2f0384c81513069
Merged-In: Id31f2159eaff6f6c018cc6b7b2f0384c81513069
(cherry picked from commit eca74f68db448bdeddd3e3353584bd8206ec09dc)
1 file changed