monitor: resurrect handle_qmp_command trace event

Commit 104fc3027960dd2aa9d310936a6cb201c60e1088 ("qmp: Drop duplicated
QMP command object checks") removed the call to
trace_handle_qmp_command() while eliminating code duplication.

This patch brings the trace event back so QEMU-internal trace events can
be correlated with the QMP commands that caused them.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20170605104216.22429-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/trace-events b/trace-events
index 6fe7818..fd83087 100644
--- a/trace-events
+++ b/trace-events
@@ -46,6 +46,7 @@
 monitor_protocol_event_emit(uint32_t event, void *data) "event=%d data=%p"
 monitor_protocol_event_queue(uint32_t event, void *qdict, uint64_t rate) "event=%d data=%p rate=%" PRId64
 handle_hmp_command(void *mon, const char *cmdline) "mon %p cmdline: %s"
+handle_qmp_command(void *mon, const char *req) "mon %p req: %s"
 
 # dma-helpers.c
 dma_blk_io(void *dbs, void *bs, int64_t offset, bool to_dev) "dbs=%p bs=%p offset=%" PRId64 " to_dev=%d"