tools/power turbostat: Add checks for failure of fgets() and fscanf()

Most calls to fgets() and fscanf() are followed by error checks.
Add an exit-on-error in the remaining cases.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Len Brown <len.brown@intel.com>
1 file changed