tst_QStorageInfo::caching is flaky on RHEL

8115: ********* Start testing of tst_QStorageInfo *********
FAIL!  : tst_QStorageInfo::caching() The computed value is expected to be different from the baseline, but is not
   Computed (free)                : 45339521024
   Baseline (storage2.bytesFree()): 45339521024
   Loc: [/home/qt/work/qt/qtbase/tests/auto/corelib/io/qstorageinfo/tst_qstorageinfo.cpp(238)]
Totals: 10 passed, 1 failed, 0 skipped, 0 blacklisted, 9ms