Revert "[test-suite] Signal error if llvm-lit was not found"

As disscussed in post-commit review, the LIT is not specified
in the zorg/buildbot/builders/ClangBuilder.py, so this broke
all test-suite bots. That is a bot problem,
i'm pulling the commit until is is resolved.

This reverts commit r364388.

llvm-svn: 364448
1 file changed