Fix warnings in linking tcmalloc

warning: hidden symbol 'pthread_atfork' in libpthread_nonshared.a(pthread_atfork.oS) is referenced by DSO libtcmalloc_minimal.so
BUG: 111076027

Change-Id: If460cba2188d5c5db2d49511d2870585893ea3c9
Signed-off-by: Weilun Du <wdu@google.com>
diff --git a/sysroot/usr/lib/libpthread.so b/sysroot/usr/lib/libpthread.so
index f02ce72..ca8dbee 100644
--- a/sysroot/usr/lib/libpthread.so
+++ b/sysroot/usr/lib/libpthread.so
@@ -2,4 +2,4 @@
    Use the shared library, but some functions are only in
    the static library, so try that secondarily.  */
 OUTPUT_FORMAT(elf64-x86-64)
-GROUP ( libpthread.so.0 libpthread_nonshared.a )
+GROUP ( libpthread.so.0 libpthread.a )