[6.0] 52e8fb15a Also exclude backtrace_symbols

[Federico G. Schwindt]

commit 52e8fb15a6a39be0820c5449174f2441b29448ee
Author: Federico G. Schwindt <fgsch at lodoss.net>
Date:   Fri Mar 30 12:16:58 2018 -0300

    Also exclude backtrace_symbols

diff --git a/tools/lsan.suppr b/tools/lsan.suppr
index 67ea016a0..89bc6c707 100644
--- a/tools/lsan.suppr
+++ b/tools/lsan.suppr
@@ -18,4 +18,6 @@ leak:binheap_new
 # ev
 leak:mct_callback
 #
+leak:backtrace_symbols
+#
 leak:vsmw_newcluster