ART: Do not log non-swap usage

Reduce logcat noise.

Bug: 20501758
Change-Id: I5cbc28614d4be9e7fd120b7ccb97ca489e341f54
diff --git a/dex2oat/dex2oat.cc b/dex2oat/dex2oat.cc
index 2a3a346..b764095 100644
--- a/dex2oat/dex2oat.cc
+++ b/dex2oat/dex2oat.cc
@@ -1217,9 +1217,9 @@
       if (!UseSwap(image_, dex_files_)) {
         close(swap_fd_);
         swap_fd_ = -1;
-        LOG(INFO) << "Decided to run without swap.";
+        VLOG(compiler) << "Decided to run without swap.";
       } else {
-        LOG(INFO) << "Accepted running with swap.";
+        LOG(INFO) << "Large app, accepted running with swap.";
       }
     }
     // Note that dex2oat won't close the swap_fd_. The compiler driver's swap space will do that.