fix compiler error when building with gnu-5 toolchain (eg as currently shipped with crystax.org android ndk, and presumably soon with android studio).

"ts_perf.cpp ....error: 'errno' was not declared in this scope
      int err=errno;"

modules/ts/src/ts_perf.cpp

@@ -41,6 +41,7 @@ static bool         log_power_checkpoints;
 
 #include <sys/syscall.h>
 #include <pthread.h>
+#include <cerrno>
 static void setCurrentThreadAffinityMask(int mask)
 {
     pid_t pid=gettid();