bionic: Check /sys/kernel/tracing for tracefs

tracefs will be mounted at /sys/kernel/tracing when debugfs
is not mounted.

Bug: 134669095
Test: atest bionic-unit-tests-static
Change-Id: Ic224cf13500efc570da8b6a27ce925bbcf068fdd
diff --git a/libc/bionic/bionic_systrace.cpp b/libc/bionic/bionic_systrace.cpp
index 1140d2d..fd97712 100644
--- a/libc/bionic/bionic_systrace.cpp
+++ b/libc/bionic/bionic_systrace.cpp
@@ -46,7 +46,10 @@
 static int get_trace_marker_fd() {
   g_lock.lock();
   if (g_trace_marker_fd == -1) {
-    g_trace_marker_fd = open("/sys/kernel/debug/tracing/trace_marker", O_CLOEXEC | O_WRONLY);
+    g_trace_marker_fd = open("/sys/kernel/tracing/trace_marker", O_CLOEXEC | O_WRONLY);
+    if (g_trace_marker_fd == -1) {
+      g_trace_marker_fd = open("/sys/kernel/debug/tracing/trace_marker", O_CLOEXEC | O_WRONLY);
+    }
   }
   g_lock.unlock();
   return g_trace_marker_fd;