AArch64: Regression: JVM crashes if manually offline a core

To reproduce:

echo 0 > /sys/devices/system/cpu/cpu1/online

jdk-16+22-rcacce843-2020-10-31-07-45-58-b3146-C8-64K/bin/java -version
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (vm_version_linux_aarch64.cpp:171), pid=91196, tid=91197
# guarantee(cpu_lines == os::processor_count()) failed: core count should be consistent
#
# JRE version: (16.0+22) (build )
# Java VM: OpenJDK 64-Bit Server VM (16+22, mixed mode, sharing, tiered, compressed oops, g1 gc, linux-aarch64)
# Problematic frame:
# V [libjvm.so+0x3c6a48] VM_Version::initialize()+0x168
#
# Core dump will be written. Default location: Core dumps may be processed with "/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %e" (or dumping to /home/amptest/jdkbuilds/jdk/core.91196)
#
# An error report file with more information is saved as:
# /home/amptest/jdkbuilds/jdk/hs_err_pid91196.log
#
#
Aborted (core dumped)

Suggest to remove this check "guarantee(cpu_lines == os::processor_count())", and the "cpu_lines" counter if not very necessary at all.

https://github.com/openjdk/jdk/blob/fe7672bac62b8493bfe01904932925385b592015/src/hotspot/os_cpu/linux_aarch64/vm_version_linux_aarch64.cpp#L171