MPIPL: Update MDRT count only if its valid

Commit 529bf93 added new attribute to save MDRT count (MPIPL_HB_MDRT_COUNT).
This commit un-conditionally updates MDRT count in call_host_runtime_setup().

At present OPAL doesn't support MPIPL and hence its not updating MDRT ntuple
in SPIRAH...resulting in writeActualCount() to  fail. And we endup in system
terminate state (at least in FSP system).

Lets make sure attribute contains valid MDRT count before calling
saveActualCount().

Change-Id: I8d25a274d65034bca392137e4f48b8a127fa4ee0
Fixes: 529bf93 (Use Attr to Save/Fetch MDRT Count)
CC: Raja Das <rajadas2@in.ibm.com>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/66474
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Reviewed-by: Dean Sanner <dsanner@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

src/usr/isteps/istep21/call_host_runtime_setup.C

@@ -830,7 +830,11 @@ void* call_host_runtime_setup (void *io_pArgs)
             uint32_t l_mdrtCount =
                 l_sys->getAttr<TARGETING::ATTR_MPIPL_HB_MDRT_COUNT>();
             //Update actual count in RUNTIME
-            RUNTIME::saveActualCount(RUNTIME::MS_DUMP_RESULTS_TBL, l_mdrtCount);
+            if(l_mdrtCount)
+            {
+                RUNTIME::saveActualCount( RUNTIME::MS_DUMP_RESULTS_TBL,
+                                          l_mdrtCount);
+            }
         }
 
         //Update the MDRT value (for MS Dump)