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)

src/scriptfile.c

@@ -1652,7 +1652,11 @@ ex_scriptnames(exarg_T *eap)
 	{
 	    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();
 	}
 }
 

src/testdir/test_scriptnames.vim

@@ -23,6 +23,10 @@ func Test_scriptnames()
 
   bwipe
   call delete('Xscripting')
+
+  let msgs = execute('messages')
+  scriptnames
+  call assert_equal(msgs, execute('messages'))
 endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4133,
 /**/
     4132,
 /**/