Upstream reports a race condition in the test added under RHEL-46729.

This test has a race condition: more than one thread can report end-of-file because the check for this condition is separate from the fread call.  It is possible that all threads return from their fread calls before feof is called on multiple threads.  This test bug is quite visible on larger AArch64 systems, for example.

Upstream thread

We should fix this before it interferes with downstream testing.