intel_rdt: fix a bunch of warnings

intel_rdt: fix a bunch of warnings

  CC       src/intel_rdt_la-intel_rdt.lo
src/intel_rdt.c: In function ‘rdt_is_core_id_valid’:
src/intel_rdt.c:163:21: warning: comparison of integer expressions of different signedness: ‘int’ and ‘unsigned int’ [-Wsign-compare]
   for (int i = 0; i < g_rdt->pqos_cpu->num_cores; i++)
                     ^
src/intel_rdt.c:164:17: warning: comparison of integer expressions of different signedness: ‘int’ and ‘unsigned int’ [-Wsign-compare]
     if (core_id == g_rdt->pqos_cpu->cores[i].lcore)
                 ^~
src/intel_rdt.c: In function ‘rdt_config_cgroups’:
src/intel_rdt.c:208:21: warning: comparison of integer expressions of different signedness: ‘int’ and ‘unsigned int’ [-Wsign-compare]
   for (int i = 0; i < g_rdt->cap_mon->u.mon->num_events; i++)
                     ^
src/intel_rdt.c: In function ‘rdt_read’:
src/intel_rdt.c:389:21: warning: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
   for (int i = 0; i < g_rdt->num_groups; i++) {
                     ^
src/intel_rdt.c: In function ‘rdt_init’:
src/intel_rdt.c:428:21: warning: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
   for (int i = 0; i < g_rdt->num_groups; i++) {
                     ^
src/intel_rdt.c: In function ‘rdt_shutdown’:
src/intel_rdt.c:451:21: warning: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
   for (int i = 0; i < g_rdt->num_groups; i++) {
                     ^
  CC       src/intel_rdt_la-utils_config_cores.lo
src/utils_config_cores.c: In function ‘check_core_grouping’:
src/utils_config_cores.c:166:23: warning: comparison of integer expressions of different signedness: ‘long int’ and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
     if ((end - start) >= out_size) {
                       ^~
  CCLD     intel_rdt.la