lib/bug: cleanup comment style, types and modernize logging

lib/bug: cleanup comment style, types and modernize logging

Improve the overall code quality of lib/bug.c by:
- Reformatting the main documentation block to follow the standard
  kernel multi-line comment style.
- Replacing 'unsigned' with the preferred 'unsigned int'.
- Converting legacy printk() calls to modern pr_warn() and pr_info()
  macros to include proper facility levels and satisfy checkpatch.

Link: https://lore.kernel.org/20260504201607.56932-1-lucasp.linux@gmail.com
Signed-off-by: Lucas Poupeau <lucasp.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>