Be sure to pick up any group error with group_reporting

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/stat.c b/stat.c
index 07c9b62..7d93abd 100644
--- a/stat.c
+++ b/stat.c
@@ -651,11 +651,21 @@
 		members++;
 
 		if (!ts->groupid) {
+			/*
+			 * These are per-group shared already
+			 */
 			ts->name = td->name;
 			ts->description = td->description;
-			ts->error = td->error;
 			ts->groupid = td->groupid;
+
+			/*
+			 * first pid in group, not very useful...
+			 */
 			ts->pid = td->pid;
+		}
+
+		if (td->error && !ts->error) {
+			ts->error = td->error;
 			ts->verror = td->verror;
 		}