[SampleFDO] Fix a bug in getOrCompHotCountThreshold/getOrCompColdCountThreshold

getOrCompHotCountThreshold/getOrCompColdCountThreshold introduced in
https://reviews.llvm.org/D45377 contain a bad mistake and will only return 1 or 0
instead of the true hot/cold cutoff value. The patch fixes the mistake. But the
mistake seems not causing big performance difference according to internal server
benchmarks testing.

Differential Revision: https://reviews.llvm.org/D50370

llvm-svn: 339162