Formatting errors -- syntax errors -- are errors, no matter which pass
they end up in. ERR_PASS1 is just plain crazy: if we end up with a
formatting error on the code-generation pass, we are in a world of
hurt.
Defer warnings to the code-generation pass; that's the pass which
matters value-wise, and that way we get the warnings in the list file,
too.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>