RFR: JDK-8261167: print_process_memory_info add a close call after fopen [v2]

[Matthias Baesken]

> Hello, there is an fopen call opening "proc/self/status" in print_process_memory_info in os_linux.cpp. This call should also have a corresponding fclose-call.
> 
> See also the Sonar finding ("Opened stream never closed. Potential resource leak") :
> https://sonarcloud.io/project/issues?id=shipilev_jdk&open=AXck8BNvBBG2CXpcnaeA&resolved=false&severities=BLOCKER&types=BUG

Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:

  Add explicit NULL check and output in failure case

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/2409/files
  - new: https://git.openjdk.java.net/jdk/pull/2409/files/a03fa5fe..858ea536

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=2409&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=2409&range=00-01

  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2409.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2409/head:pull/2409

PR: https://git.openjdk.java.net/jdk/pull/2409