Make all FATAL-related output appear as 'F' log output.

Previously most of the spew belonging to a FATAL would be 'E' because
Runtime::Abort() used LOG(ERROR) to avoid recursion.

Change-Id: If8f62586c302c239e827c5235ed58ee8fe6e8f5e
diff --git a/src/logging_linux.cc b/src/logging_linux.cc
index 2c1d699..f3a6cf3 100644
--- a/src/logging_linux.cc
+++ b/src/logging_linux.cc
@@ -34,7 +34,7 @@
 }
 
 void LogMessage::LogLine(const char* line) {
-  std::cerr << "VDIWEF"[data_->severity] << ' '
+  std::cerr << "VDIWEFF"[data_->severity] << ' '
             << StringPrintf("%5d %5d", getpid(), ::art::GetTid()) << ' '
             << data_->file << ':' << data_->line_number << "] " << line << std::endl;
 }