cmd/geth, mobile: add memsize to pprof server (#16532)

* cmd/geth, mobile: add memsize to pprof server

This is a temporary change, to be reverted before the next release.

* cmd/geth: fix variable name

cmd/geth/main.go

@@ -223,6 +223,8 @@ func geth(ctx *cli.Context) error {
 // it unlocks any requested accounts, and starts the RPC/IPC interfaces and the
 // miner.
 func startNode(ctx *cli.Context, stack *node.Node) {
+	debug.Memsize.Add("node", stack)
+
 	// Start up the node itself
 	utils.StartNode(stack)