crimson/osd: print notify_id instead of its address

crimson/osd: print notify_id instead of its address

this addresses the FTBFS like

    /usr/include/fmt/core.h:902:19: error: static assertion failed: formatting of non-void pointers is disallowed
      902 |     static_assert(!sizeof(T), "formatting of non-void pointers is disallowed");
          |                   ^~~~~~~~~~

also, i think it is more helpful in this context to have the
notify id instead of the address, as we can use the id to reference
the notification printed by other logging messages.

Signed-off-by: Kefu Chai <kchai@redhat.com>