RFR: 8255716: AArch64: Regression: JVM crashes if manually offline a core

[Patrick Zhang]

Please review this change that removed the unnecessary check **cpu_lines == os::processor_count()** from VM_Version::get_os_cpu_info inside src/hotspot/os_cpu/linux_aarch64/vm_version_linux_aarch64.cpp. 

This **assertion** is practically not needed. While a test system with some cores intentionally turned off, e.g. via echo 0 > /sys/devices/system/cpu/cpu1/online, **java -version** would crash, building openjdk on this system would fail too. 

This regression issue was introduced by https://github.com/openjdk/jdk/commit/ec9bee68

Testing:
- java -version, building openjdk as smoke tests
- jtreg tier1 as sanity check

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Commit messages:
 - AArch64: Remove unnecessary check cpu_lines == os::processor_count()

Changes: https://git.openjdk.java.net/jdk/pull/983/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=983&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8255716
  Stats: 3 lines in 1 file changed: 0 ins; 3 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/983.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/983/head:pull/983

PR: https://git.openjdk.java.net/jdk/pull/983