pthread-timers: Hide internal symbol __timer_table_start_stop

Change-Id: If99c5816fe6fa9107aa6bef4697048fabf92283f
diff --git a/libc/bionic/pthread-timers.c b/libc/bionic/pthread-timers.c
index 7b9c99e..ae04029 100644
--- a/libc/bionic/pthread-timers.c
+++ b/libc/bionic/pthread-timers.c
@@ -260,7 +260,7 @@
  ** requirements: the timers of fork child processes must be
  ** disarmed but not deleted.
  **/
-void
+__LIBC_HIDDEN__ void
 __timer_table_start_stop( int  stop )
 {
     if (__timer_table != NULL) {