Remove a spurious newline from Flo's log2 generation rule

This is actually pretty straight-forward: there is a '\n' at the end
of the log2 rule, which isn't there anywhere else.  I've already
worked around this in libflo, but I figured I'd just fix it because
it's kind of silly.
Merge pull request #232 from palmer-dabbelt/flo-log2

Remove a spurious newline from Flo's log2 generation rule