crash_dump: use sysfs_emit in sysfs show functions

crash_dump: use sysfs_emit in sysfs show functions

Replace sprintf() with sysfs_emit() in sysfs show functions.  sysfs_emit()
is preferred for formatting sysfs output because it provides safer bounds
checking.  No functional changes.

Link: https://lkml.kernel.org/r/20260301125106.911980-2-thorsten.blum@linux.dev
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>