patch 8.2.4133: output of ":scriptnames" goes into the message history

Problem:    output of ":scriptnames" goes into the message history, while this
            des not happen for other commands, such as ":ls".
Solution:   Use msg_outtrans() instead of smsg(). (closes #9551)
diff --git a/src/scriptfile.c b/src/scriptfile.c
index 3508139..159c9fc 100644
--- a/src/scriptfile.c
+++ b/src/scriptfile.c
@@ -1652,7 +1652,11 @@
 	{
 	    home_replace(NULL, SCRIPT_ITEM(i)->sn_name,
 						    NameBuff, MAXPATHL, TRUE);
-	    smsg("%3d: %s", i, NameBuff);
+	    vim_snprintf((char *)IObuff, IOSIZE, "%3d: %s", i, NameBuff);
+	    msg_putchar('\n');
+	    msg_outtrans(IObuff);
+	    out_flush();	    // output one line at a time
+	    ui_breakcheck();
 	}
 }