Using the correct time for wait_start_ms when lock contention logging is enabled

Bug: 17208457
Change-Id: I35555e0acf3b37bb3776a62c64d59ae93403b237
(cherry picked from commit b894a19dfd668b6779de939cf5265b7e409d8809)
diff --git a/runtime/monitor.cc b/runtime/monitor.cc
index 5dd16ef..a87d7c1 100644
--- a/runtime/monitor.cc
+++ b/runtime/monitor.cc
@@ -238,7 +238,7 @@
     }
     // Contended.
     const bool log_contention = (lock_profiling_threshold_ != 0);
-    uint64_t wait_start_ms = log_contention ? 0 : MilliTime();
+    uint64_t wait_start_ms = log_contention ? MilliTime() : 0;
     mirror::ArtMethod* owners_method = locking_method_;
     uint32_t owners_dex_pc = locking_dex_pc_;
     // Do this before releasing the lock so that we don't get deflated.