Merge pull request #13478 from xiaoxichen/fix_osdc_perfcounter

osdc: fix osdc_osd_seesion perf counter.

Reviewed-by: Sage Weil <sage@redhat.com>
Reviewed-by: Kefu Chai <kchai@redhat.com>

src/osdc/Objecter.cc

@@ -1718,7 +1718,7 @@ int Objecter::_get_session(int osd, OSDSession **session, shunique_lock& sul)
   s->con = messenger->get_connection(osdmap->get_inst(osd));
   s->con->set_priv(s->get());
   logger->inc(l_osdc_osd_session_open);
-  logger->inc(l_osdc_osd_sessions, osd_sessions.size());
+  logger->set(l_osdc_osd_sessions, osd_sessions.size());
   s->get();
   *session = s;
   ldout(cct, 20) << __func__ << " s=" << s << " osd=" << osd << " "