Fix linux build.

src/Cpu_unix.cpp

@@ -22,3 +22,38 @@
  */
 
 
+#include <pthread.h>
+#include <sched.h>
+#include <unistd.h>
+
+
+#include "Cpu.h"
+
+
+void Cpu::init()
+{
+#   ifdef XMRIG_NO_LIBCPUID
+    m_totalThreads = sysconf(_SC_NPROCESSORS_CONF);
+#   endif
+
+    initCommon();
+}
+
+
+void Cpu::setAffinity(int id, unsigned long mask)
+{
+    cpu_set_t set;
+    CPU_ZERO(&set);
+
+    for (int i = 0; i < m_totalThreads; i++) {
+        if (mask & (1UL << i)) {
+            CPU_SET(i, &set);
+        }
+    }
+
+    if (id == -1) {
+        sched_setaffinity(0, sizeof(&set), &set);
+    } else {
+        pthread_setaffinity_np(pthread_self(), sizeof(&set), &set);
+    }
+}