[NFC][sanitizer] Use nullptr instead of 0

GitOrigin-RevId: 8bce263820096d7c7921354b7646fbb6bb1b8cfb
diff --git a/lib/sanitizer_common/sanitizer_tls_get_addr.cpp b/lib/sanitizer_common/sanitizer_tls_get_addr.cpp
index 5e9a787..087bd80 100644
--- a/lib/sanitizer_common/sanitizer_tls_get_addr.cpp
+++ b/lib/sanitizer_common/sanitizer_tls_get_addr.cpp
@@ -129,7 +129,7 @@
   uptr dso_id = arg->dso_id;
   DTLS::DTV *dtv = DTLS_Find(dso_id);
   if (!dtv || dtv->beg)
-    return 0;
+    return nullptr;
   uptr tls_size = 0;
   uptr tls_beg = reinterpret_cast<uptr>(res) - arg->offset - kDtvOffset;
   VReport(2,