qmp: Replace get_qmp_greeting() by qmp_greeting()

get_qmp_greeting() returns a QDict * as QObject *.  It's caller
converts it right back.

Return QDict * instead.  While there, rename to qmp_greeting().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180703085358.13941-26-armbru@redhat.com>
1 file changed