[compiler-rt] fix failing debug_locate.cc test due to a leak

New test from r218481 fails on Linux due to LeakSanitizer reporting a leak, this patch frees the memory properly. 



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@218483 91177308-0d34-0410-b5e6-96231b3b80d8