ENH: hostCollated: revert to collated naming if running on single proc

src/OpenFOAM/global/fileOperations/collatedFileOperation/collatedFileOperation.C

@@ -573,6 +573,10 @@ Foam::word Foam::fileOperations::collatedFileOperation::processorsDir
                         break;
                     }
                 }
+
+                // Add range if not all processors
+                if (maxProc-minProc+1 != nProcs_)
+                {
                     procDir +=
                       + "_"
                       + Foam::name(minProc)
@@ -580,6 +584,7 @@ Foam::word Foam::fileOperations::collatedFileOperation::processorsDir
                       + Foam::name(maxProc);
                 }
             }
+        }
 
         return procDir;
     }