move sensors into ipmi::sensor namespace

The object was left in the global namespace, but the type was in the
ipmi::sensor namespace.  Move the object into the namespace.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I88e46da4abda220d3b6fcc2ea64b8ef0decb0dc3
diff --git a/scripts/writesensor.mako.cpp b/scripts/writesensor.mako.cpp
index 192b858..c740f6f 100644
--- a/scripts/writesensor.mako.cpp
+++ b/scripts/writesensor.mako.cpp
@@ -27,7 +27,9 @@
 #include "sensordatahandler.hpp"
 
 #include <ipmid/types.hpp>
-using namespace ipmi::sensor;
+
+namespace ipmi {
+namespace sensor {
 
 extern const IdInfoMap sensors = {
 % for key in sensorDict.iterkeys():
@@ -145,3 +147,5 @@
 % endfor
 };
 
+} // namespace sensor
+} // namespace ipmi