Revert "Linux: Turn --icf=safe back on for the gold linker."

This broke the wtf_unittests when compiling with gcc:
http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20%28dbg%29/builds/16904

TBR=cevans@chromium.org, thestig@chromium.org
BUG=

Review URL: https://codereview.chromium.org/139153005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245194 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245194