osdc/Objecter: normalize watch error (ENOENT on delete)

Signed-off-by: Sage Weil <sage@redhat.com>
ceph_test_rados_api_watch_notify: print err to debug

Signed-off-by: Sage Weil <sage@redhat.com>
ceph_test_rados_api_watch_notify: use GT macro

so we can see the value

Signed-off-by: Sage Weil <sage@redhat.com>
ceph_test_rados_api_watch_notify: fix a zillion warnings

Signed-off-by: Sage Weil <sage@redhat.com>