phosphor-fan-presence elog error exception.

Implemented elog exception for phosphor fan presence,
replacing runtime_errors.

Change-Id: I70465060838b2cbaeadccf84ed5924e222ac59e3
Signed-off-by: Dinesh Chinari <chinari@us.ibm.com>
diff --git a/presence/fan_enclosure.cpp b/presence/fan_enclosure.cpp
index ca97c07..7b412bd 100644
--- a/presence/fan_enclosure.cpp
+++ b/presence/fan_enclosure.cpp
@@ -67,15 +67,7 @@
         ObjectMap invObj = getObjectMap(curPresState);
         // Get inventory manager service name from mapper
         std::string invService;
-        try
-        {
-            invService = phosphor::fan::util::getInvService(bus);
-        }
-        catch (const std::runtime_error& err)
-        {
-            log<level::ERR>(err.what());
-            return;
-        }
+        invService = phosphor::fan::util::getInvService(bus);
         // Update inventory for this fan
         auto invMsg = bus.new_method_call(invService.c_str(),
                                           INVENTORY_PATH,