Move consistency check for number of threads
Recent refactoring meant that the count of threads known to OpenMP was
only used to provide a consistency check in the fallback case of
sysconf detection.
Note that no version of the HardwareTopology code ever used
information from OpenMP as an input.
Parameters for implementing warnings currently remain in
HardwareTopology::detect(), so that the sysconf case can continue to
handle cases where we think we know how to advise the user. This
will go away in master branch with the new logging module.
Change-Id: Iaf383abc420d2f04b6514e8856c9f1414cbba55c