tools/power turbostat: Fix --cpu-set 0 regression on HT systems

tools/power turbostat: Fix --cpu-set 0 regression on HT systems

"turbostat --cpu-set 0" appears to hang if cpu0 has an HT sibling.

This is because the initialization code recognizes that it does not
have to open perf files for the HT sibling, but the HT support
in the collection code sees the HT sibling and tries to read
from an uninitialized file descriptor, 0 (standard input).

Access HT siblings only when they are in the allowed set.

Fixes: a2b4d0f8bf07 ("tools/power turbostat: Favor cpu# over core#")
Signed-off-by: Len Brown <len.brown@intel.com>
Reported-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>