rfifolock: no need to get thread identifier when nesting

Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Message-id: 1462874348-32396-1-git-send-email-xiecl.fnst@cn.fujitsu.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

util/rfifolock.c

@@ -58,9 +58,9 @@ void rfifolock_lock(RFifoLock *r)
             }
             qemu_cond_wait(&r->cond, &r->lock);
         }
+        qemu_thread_get_self(&r->owner_thread);
     }
 
-    qemu_thread_get_self(&r->owner_thread);
     r->nesting++;
     qemu_mutex_unlock(&r->lock);
 }