Do not put /usr/lib in SCons LIBPATH
Do not put /usr/lib in SCons LIBPATH

See r9895 for the rationale for this change.  This is another
place in which SConstruct wrongly told SCons explicitly about
a standard library directory, with bad effects depending on
local configuration.

BUG= none
TEST= trybots

R=ncbray@google.com

Review URL: https://codereview.chromium.org/11038019

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@9906 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,sbc100/native_client