Hide oc_main_poll()

Since the poll loop is now in the jni layer, there is no need
to expose oc_main_poll() as a public api.

Change-Id: Idc744b917854623b14e418c0c295674fdcb51bef
Signed-off-by: Larry Sachs <larry.j.sachs@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/29395Tested-by: IoTivity Jenkins <jenkins-daemon@iotivity.org>
Reviewed-by: George Nash <george.nash@intel.com>
Reviewed-by: Rick Bell <richard.s.bell@intel.com>

swig/swig_interfaces/oc_api.i

@@ -335,7 +335,7 @@ int jni_main_init(const oc_handler_t *handler)
   return return_value;
 }
 %}
-%rename(mainPoll) oc_main_poll;
+%ignore oc_main_poll;
 %ignore oc_main_shutdown;
 %rename(mainShutdown) jni_main_shutdown;
 %inline %{