Update LSAN suppressions.

Seems the obvious thing works now.

Ran nanobench,
-----------------------------------------------------
Suppressions used:
  count      bytes template
    586    3530064 libGL.so
-----------------------------------------------------

and dm,
-----------------------------------------------------
Suppressions used:
  count      bytes template
    340    2048160 libGL.so
-----------------------------------------------------

BUG=skia:
R=robertphillips@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/517133002
diff --git a/Makefile b/Makefile
index f8ec875..29831bb 100644
--- a/Makefile
+++ b/Makefile
@@ -40,7 +40,7 @@
 # TODO(epoger): I'm not sure if the above comment is still valid in a ninja
 # world.
 VALID_TARGETS := \
-                 bench \
+                 nanobench \
                  debugger \
                  dm \
                  everything \