Fix debug output in bechordal's handle_constraints.
Fix debug output in bechordal's handle_constraints.

The so-called "bit set" was not a bit set, but a raw bit set, for which
we have no format conversion in ir_printf.

MatzeB/libfirm,libfirm/libfirm,MatzeB/libfirm,MatzeB/libfirm,MatzeB/libfirm,MatzeB/libfirm,libfirm/libfirm,MatzeB/libfirm,MatzeB/libfirm,libfirm/libfirm,libfirm/libfirm,libfirm/libfirm