Use CPU_SET_S instead of CPU_SET

Fix incorrect use of CPU_SET on variable size cpu_set_t

Suggested by Christopher E. Moore on github
https://github.com/RadeonOpenCompute/ROCR-Runtime/issues/130

Change-Id: I710b56683ba07c08dcd83c851bf72e4f127a0ad4

runtime/hsa-runtime/core/util/lnx/os_linux.cpp

@@ -120,7 +120,7 @@ class os_thread {
       }
       CPU_ZERO_S(CPU_ALLOC_SIZE(cores), cpuset);
       for (int i = 0; i < cores; i++) {
-        CPU_SET(i, cpuset);
+        CPU_SET_S(i, CPU_ALLOC_SIZE(cores), cpuset);
       }
       err = pthread_attr_setaffinity_np(&attrib, CPU_ALLOC_SIZE(cores), cpuset);
       CPU_FREE(cpuset);