monitor/hmp: print trace as option in help for log command

The below is printed when printing help information in qemu-system-x86_64
command line, and when CONFIG_TRACE_LOG is enabled:

----------------------------
$ qemu-system-x86_64 -d help
... ...
trace:PATTERN   enable trace events

Use "-d trace:help" to get a list of trace events.
----------------------------

However, the options of "trace:PATTERN" are only printed by
"qemu-system-x86_64 -d help", but missing in hmp "help log" command.

Fixes: c84ea00d ("log: add "-d trace:PATTERN"")
Cc: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Message-Id: <20220831213943.8155-1-dongli.zhang@oracle.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

monitor/hmp.c

@@ -285,10 +285,15 @@ void help_cmd(Monitor *mon, const char *name)
         if (!strcmp(name, "log")) {
             const QEMULogItem *item;
             monitor_printf(mon, "Log items (comma separated):\n");
-            monitor_printf(mon, "%-10s %s\n", "none", "remove all logs");
+            monitor_printf(mon, "%-15s %s\n", "none", "remove all logs");
             for (item = qemu_log_items; item->mask != 0; item++) {
-                monitor_printf(mon, "%-10s %s\n", item->name, item->help);
+                monitor_printf(mon, "%-15s %s\n", item->name, item->help);
             }
+#ifdef CONFIG_TRACE_LOG
+            monitor_printf(mon, "trace:PATTERN   enable trace events\n");
+            monitor_printf(mon, "\nUse \"log trace:help\" to get a list of "
+                           "trace events.\n\n");
+#endif
             return;
         }