tsan: fix test

this test is flaky because of ASLR
app memory is 7e8000000000-800000000000,
there may or may not be a 1TB hole depending on
where ASLR will choose to map libraries



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@223469 91177308-0d34-0410-b5e6-96231b3b80d8