Build our benchmarks against glibc too.

Bug: 18556607
Change-Id: I455ac8b93c0835836180e549486bc52d393ee6a6
diff --git a/libc/bionic/pthread_atfork.cpp b/libc/bionic/pthread_atfork.cpp
index 82e2b59..d1c4ad0 100644
--- a/libc/bionic/pthread_atfork.cpp
+++ b/libc/bionic/pthread_atfork.cpp
@@ -44,7 +44,7 @@
   atfork_t* last;
 };
 
-static pthread_mutex_t g_atfork_list_mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER;
+static pthread_mutex_t g_atfork_list_mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
 static atfork_list_t g_atfork_list = { NULL, NULL };
 
 void __bionic_atfork_run_prepare() {
@@ -73,7 +73,7 @@
     }
   }
 
-  g_atfork_list_mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER;
+  g_atfork_list_mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
 }
 
 void __bionic_atfork_run_parent() {