[XRay] Use correct type for thread ID parsing

Previously we were reading only a uint16_t when we really needed to read
an int32_t from the log.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341239 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed