disas/cris: Pass buffer size to format_dec() to avoid overflow warning

disas/cris: Pass buffer size to format_dec() to avoid overflow warning

Propagate the buffer size to format_dec() and use snprintf().

This should silence this UBSan -Wformat-overflow warning:

  In file included from /usr/include/stdio.h:906,
                   from include/qemu/osdep.h:114,
                   from ../disas/cris.c:21:
  In function 'sprintf',
      inlined from 'format_dec' at ../disas/cris.c:1737:3,
      inlined from 'print_with_operands' at ../disas/cris.c:2477:12,
      inlined from 'print_insn_cris_generic.constprop' at ../disas/cris.c:2690:8:
  /usr/include/bits/stdio2.h:30:10: warning: null destination pointer [-Wformat-overflow=]
   30 |   return __builtin___sprintf_chk (__s, __USE_FORTIFY_LEVEL - 1,
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   31 |                                   __glibc_objsize (__s), __fmt,
      |                                   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   32 |                                   __va_arg_pack ());
      |                                   ~~~~~~~~~~~~~~~~~

Reported-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20231120132222.82138-1-philmd@linaro.org>
[Rewritten to fix logic and avoid repeated expression. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>