sysfs: Removed unused headers

Also put fstream in the right place.

Change-Id: I3c199c49f6c4068f0483b923f51dc4750aa42596
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/sysfs.cpp b/sysfs.cpp
index efdba92..ca22fe8 100644
--- a/sysfs.cpp
+++ b/sysfs.cpp
@@ -15,14 +15,13 @@
  */
 #include <cstdlib>
 #include <experimental/filesystem>
+#include <fstream>
 #include <memory>
 #include <phosphor-logging/elog.hpp>
 #include <phosphor-logging/elog-errors.hpp>
 #include <xyz/openbmc_project/Control/Device/error.hpp>
 #include <xyz/openbmc_project/Sensor/Device/error.hpp>
 #include "sysfs.hpp"
-#include "util.hpp"
-#include <fstream>
 
 using namespace phosphor::logging;
 namespace fs = std::experimental::filesystem;