SERVER-8070 Notify primary after each batch, not after each op

Author: kchodorow

src/mongo/db/oplog.cpp

@@ -98,8 +98,6 @@ namespace mongo {
                 theReplSet->lastOpTimeWritten = ts;
                 theReplSet->lastH = h;
                 ctx.getClient()->setLastOp( ts );
-
-                replset::BackgroundSync::notify();
             }
         }
     }

src/mongo/db/repl/rs_initialsync.cpp

@@ -450,6 +450,10 @@ namespace mongo {
             cx.ctx().db()->flushFiles(true);
         }
 
+        // If we just cloned & there were no ops applied, we still want the primary to know where
+        // we're up to
+        replset::BackgroundSync::notify();
+
         changeState(MemberState::RS_RECOVERING);
         sethbmsg("initial sync done",0);
     }