Fix arm trusted toolchain creator handling of unpacked symlinks
Fix arm trusted toolchain creator handling of unpacked symlinks

The script was using the (trivial) "cleanlinks" script to remove dangling
symlinks from .../usr/lib, and then manually removing one other bad
symlink.  All these links were bad only because they came from Ubuntu
packages where they were absolute links instead of relative links (as they
really should be in those Ubuntu packages).

This logic fell down when the bots were updated so that one more link
(../usr/lib/libssl.so) went from being a dangling symlink to being a
wrongly absolute link, and was not being removed.

Instead of the fragile attempt to remove links, uniformly relativize them
so that they work properly as intended in the relocated toolchain.

BUG=none
TEST=manually ran the script and verified what appears in the output tarball

R=robertm@google.com,bradnelson@google.com,ncbray@google.com

Review URL: http://codereview.chromium.org/7038049

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@5389 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

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