sim: cr16: fix build warnings

sim: cr16: fix build warnings

The printf fix is obvious enough, but the hash one is a real bug:
cr16/interp.c: In function 'sim_open':
cr16/interp.c:560:17: error: 'h' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  560 |               h = h->next;
      |               ~~^~~~~~~~~

It happens to not cause a problem currently because the first entry in
the generated table that this loop operates matches a codepath where h
is initialized.  Then when later entries don't match, the previous value
is pointing at the end of a valid hash table already, and the rest of
the code does nothing.

With this tidied up, we can delete the SIM_AC_OPTION_WARNINGS(no) call
to get the default common behavior where -Werror is enabled.