RFR: 8298038: [s390] Configure script detects num_cores +1

[Amit Kumar]

cpuinfo on s390x architecture contains additional header information on Linux/Z which is not seen on GNU Linux:


vendor_id       : IBM/S390
# processors    : 8

due to this one extra build job is created. 

Reported Issue can be found here : [JDK-8298038](https://bugs.openjdk.org/browse/JDK-8298038)

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Commit messages:
 - updates copyright header year
 - grep will count exact word match

Changes: https://git.openjdk.org/jdk/pull/11659/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11659&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8298038
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/11659.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11659/head:pull/11659

PR: https://git.openjdk.org/jdk/pull/11659