Remove vold logs related to block devices

Since every APEX requires at least one loop device, now most of the
block devices on a device are not managed by vold. This change removes
some log statements around block devices that vold is not aware of.

Test: device boots
Test: adb logcat
Change-Id: I8efa22023c1f888e75f40178fac464af4457df3c
diff --git a/VolumeManager.cpp b/VolumeManager.cpp
index 2697f67..d299593 100644
--- a/VolumeManager.cpp
+++ b/VolumeManager.cpp
@@ -239,7 +239,7 @@
             break;
         }
         case NetlinkEvent::Action::kChange: {
-            LOG(DEBUG) << "Disk at " << major << ":" << minor << " changed";
+            LOG(VERBOSE) << "Disk at " << major << ":" << minor << " changed";
             handleDiskChanged(device);
             break;
         }