qmp-commands: move 'query-migrate-cache-size' doc to schema

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

docs/qmp-commands.txt

@@ -305,19 +305,6 @@ Example:
 -> { "execute": "migrate-set-cache-size", "arguments": { "value": 536870912 } }
 <- { "return": {} }
 
-query-migrate-cache-size
-------------------------
-
-Show cache size to be used by XBZRLE migration
-
-returns a json-object with the following information:
-- "size" : json-int
-
-Example:
-
--> { "execute": "query-migrate-cache-size" }
-<- { "return": 67108864 }
-
 x-colo-lost-heartbeat
 --------------------
 

qapi-schema.json

@@ -2657,11 +2657,17 @@
 ##
 # @query-migrate-cache-size:
 #
-# query XBZRLE cache size
+# Query migration XBZRLE cache size
 #
 # Returns: XBZRLE cache size in bytes
 #
 # Since: 1.2
+#
+# Example:
+#
+# -> { "execute": "query-migrate-cache-size" }
+# <- { "return": 67108864 }
+#
 ##
 { 'command': 'query-migrate-cache-size', 'returns': 'int' }