Make our CHECK logging more useful on the target...

...by always including the filename and line number, like on the host.
We might want to only do this for CHECKs eventually, but right now
knowing exactly where the output is coming from is more useful than
brevity.

Change-Id: I24f3e6a43c3bc8279b4248ec4e67071b2c2471c5
diff --git a/src/logging_android.cc b/src/logging_android.cc
index 0d64c60..f404349 100644
--- a/src/logging_android.cc
+++ b/src/logging_android.cc
@@ -28,9 +28,11 @@
 LogMessage::LogMessage(const char* file, int line, LogSeverity severity, int error)
 : file_(file), line_number_(line), severity_(severity), errno_(error)
 {
+  const char* last_slash = strrchr(file, '/');
+  file_ = (last_slash == NULL) ? file : last_slash + 1;
 }
 
 void LogMessage::LogLine(const char* line) {
   int priority = kLogSeverityToAndroidLogPriority[severity_];
-  LOG_PRI(priority, LOG_TAG, "%s", line);
+  LOG_PRI(priority, LOG_TAG, "%s:%d] %s", file_, line_number_, line);
 }