patch 9.0.0967: leaking memory from autocmd windows

Problem:    Leaking memory from autocmd windows.
Solution:   Free window when auc_win is not NULL.
diff --git a/src/quickfix.c b/src/quickfix.c
index e8716d2..4c414e0 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -6639,10 +6639,10 @@
 
 	    // restore curwin/curbuf and a few other things
 	    aucmd_restbuf(&aco);
-	}
 
-	if (newbuf_to_wipe.br_buf != NULL && bufref_valid(&newbuf_to_wipe))
-	    wipe_buffer(newbuf_to_wipe.br_buf, FALSE);
+	    if (newbuf_to_wipe.br_buf != NULL && bufref_valid(&newbuf_to_wipe))
+		wipe_buffer(newbuf_to_wipe.br_buf, FALSE);
+	}
 
 	// Add back the "dummy" flag, otherwise buflist_findname_stat() won't
 	// skip it.