Do not check tcache clear when doing a purge.

On systems where the tcache is disabled, the tcache clear option will
fail, and not really do a purge.

Bug: 137037462
Bug: 136236080

Test: Built taimen as malloc svelte and verified the M_PURGE mallopt
Test: call failed before this fix and passes afterwards.
Change-Id: Ib30e5f3e083a9c6d046adff30f2aa7eacaf6df10
Merged-In: Ib30e5f3e083a9c6d046adff30f2aa7eacaf6df10
(cherry picked from commit 3d0bafb945bc9e39ddc84a0167e713b8e70dc135)

libc/bionic/jemalloc_wrapper.cpp

diff --git a/libc/bionic/jemalloc_wrapper.cpp b/libc/bionic/jemalloc_wrapper.cpp
index bf0494d..7d04457 100644
--- a/libc/bionic/jemalloc_wrapper.cpp
+++ b/libc/bionic/jemalloc_wrapper.cpp
@@ -107,9 +107,8 @@
     // clear the caches of other threads.
     // This must be done first so that cleared allocations get purged
     // in the next calls.
-    if (je_mallctl("thread.tcache.flush", nullptr, nullptr, nullptr, 0) != 0) {
-      return 0;
-    }
+    // Ignore the return call since this will fail if the tcache is disabled.
+    je_mallctl("thread.tcache.flush", nullptr, nullptr, nullptr, 0);
 
     unsigned narenas;
     size_t sz = sizeof(unsigned);