[crac] RFR: 8374614: [CRaC] Remove defunct fdinfo marking [v2]

[Radim Vansa]

> When initializing fdinfos, there might be a racy native thread closing FD between enumerating FDs and `readlink /proc/self/fd/XXX`, causing an error and assertion to fail.
> 
> Further looking into the code it seems that the fdinfo::mark is not read since https://github.com/openjdk/crac/commit/4b0dc2dc9722945579c9772b335a44fa79f1729f and therefore the whole check is defunct, and can be removed.

Radim Vansa has updated the pull request incrementally with one additional commit since the last revision:

  Remove unused flags field

-------------

Changes:
  - all: https://git.openjdk.org/crac/pull/284/files
  - new: https://git.openjdk.org/crac/pull/284/files/29bd3983..ce2ce45f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=crac&pr=284&range=01
 - incr: https://webrevs.openjdk.org/?repo=crac&pr=284&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.org/crac/pull/284.diff
  Fetch: git fetch https://git.openjdk.org/crac.git pull/284/head:pull/284

PR: https://git.openjdk.org/crac/pull/284