Fix the target Linux builds of ART

When ART_TARGET_LINUX was set it would hit some pieces of dead code that
were using old defines i.e. `__ANDROID__`

Test: export ART_TARGET_LINUX=true
Test: source build/envsetup.sh
Test: lunch
Test: cd art && mma

Change-Id: I80102750192928606e0884d2b723a87ccb7d7e19
diff --git a/runtime/base/logging.cc b/runtime/base/logging.cc
index 6b21a56..1dca428 100644
--- a/runtime/base/logging.cc
+++ b/runtime/base/logging.cc
@@ -80,7 +80,7 @@
     gCmdLine.reset(new std::string("<unset>"));
   }
 
-#ifdef __ANDROID__
+#ifdef ART_TARGET_ANDROID
 #define INIT_LOGGING_DEFAULT_LOGGER android::base::LogdLogger()
 #else
 #define INIT_LOGGING_DEFAULT_LOGGER android::base::StderrLogger