hmp: Name HMP command handler functions hmp_COMMAND()

Some are called do_COMMAND() (old ones, usually), some hmp_COMMAND(),
and sometimes COMMAND pointlessly differs in spelling.

Normalize to hmp_COMMAND(), where COMMAND is exactly the command name
with '-' replaced by '_'.

Exceptions:

* do_device_add() and client_migrate_info() *not* renamed to
  hmp_device_add(), hmp_client_migrate_info(), because they're also
  QMP handlers.  They still need to be converted to QAPI.

* do_memory_dump(), do_physical_memory_dump(), do_ioport_read(),
  do_ioport_write() renamed do hmp_* instead of hmp_x(), hmp_xp(),
  hmp_i(), hmp_o(), because those names are too cryptic for my taste.

* do_info_help() renamed to hmp_info_help() instead of hmp_info(),
  because it only covers help.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
diff --git a/vl.c b/vl.c
index 8c8f142..7e6e93c 100644
--- a/vl.c
+++ b/vl.c
@@ -1284,7 +1284,7 @@
     return r;
 }
 
-void do_usb_add(Monitor *mon, const QDict *qdict)
+void hmp_usb_add(Monitor *mon, const QDict *qdict)
 {
     const char *devname = qdict_get_str(qdict, "devname");
     if (usb_device_add(devname) < 0) {
@@ -1292,7 +1292,7 @@
     }
 }
 
-void do_usb_del(Monitor *mon, const QDict *qdict)
+void hmp_usb_del(Monitor *mon, const QDict *qdict)
 {
     const char *devname = qdict_get_str(qdict, "devname");
     if (usb_device_del(devname) < 0) {