Remove Unused local variable $v_result from /core/lib/Drupal/Component/Archiver/ArchiveTar.php

Part of meta-issue #2002650: [meta, no patch] improve maintainability by removing unused local variables

File /core/lib/Drupal/Component/Archiver/ArchiveTar.php

Line 404: Unused local variable $v_result
Line 442: Unused local variable $v_result
Line 501: Unused local variable $v_result
Line 556: Unused local variable $v_result
Line 1465: Unused local variable $v_result
Line 1467: Unused local variable $v_extract_all
Line 1468: Unused local variable $v_listing
Line 1504: Unused local variable $v_extract_file
Line 1673: Unused local variable $v_file_dir