lib/resctrl_monitoring.c: fix error return on failed fscanf
lib/resctrl_monitoring.c: fix error return on failed fscanf

Currently when fscanf fails the error ret is assigned to PQOS_RETVAL_ERROR
however this is never returned at the end of the function because the
value is PQOS_RETVAL_OK is hard coded as the return instead of ret. Fix
this by returning ret instead.

Signed-off-by: Colin Ian King <d100aa70785e45ee8deab668147d941941915c21@canonical.com>

01org/intel-cmt-cat,01org/intel-cmt-cat,01org/intel-cmt-cat