Fix XPC connection failure handling

[kpark-apple]

Problem

• Fix redundant completion block call when XPC connection fails in Darwin CHIPDeviceController.

Change overview

• Inserted breaking return in failure path

Testing

• A new unit test was added and observed redundant call is not made: note that the redundant call itself is harmless except for a confusing log message.

[github-actions]

PR #16063: Size comparison from 1c74a21 to 1d6b6d8

Full report (17 builds for cyw30739, efr32, esp32, k32w, linux, mbed, p6, telink)

platform	target	config	section	1c74a21	1d6b6d8	change	% change
cyw30739	light	cyw930739m2evb_01	(read/write)	598102	598102	0	0.0
			.app_xip_area	505684	505684	0	0.0
			.bss	75108	75108	0	0.0
			.data	652	652	0	0.0
			.rodata	0	0	0	0.0
			.text	0	0	0	0.0
	lock	cyw930739m2evb_01	(read/write)	555970	555970	0	0.0
			.app_xip_area	465088	465088	0	0.0
			.bss	73612	73612	0	0.0
			.data	616	616	0	0.0
			.rodata	0	0	0	0.0
			.text	0	0	0	0.0
	ota-requestor	cyw930739m2evb_01	(read/write)	565978	565978	0	0.0
			.app_xip_area	465408	465408	0	0.0
			.bss	82980	82980	0	0.0
			.data	552	552	0	0.0
			.rodata	0	0	0	0.0
			.text	112	112	0	0.0
efr32	lighting-app	BRD4161A	(read only)	919808	919808	0	0.0
			(read/write)	128256	128256	0	0.0
			.bss	126216	126216	0	0.0
			.data	2040	2040	0	0.0
			.text	919800	919800	0	0.0
		BRD4161A+rpc	(read only)	948620	948620	0	0.0
			(read/write)	144212	144212	0	0.0
			.bss	141992	141992	0	0.0
			.data	2220	2220	0	0.0
			.text	948612	948612	0	0.0
	window-app	BRD4161A	(read only)	852364	852364	0	0.0
			(read/write)	126220	126220	0	0.0
			.bss	124304	124304	0	0.0
			.data	1916	1916	0	0.0
			.text	852356	852356	0	0.0
esp32	all-clusters-app	c3devkit	(read only)	957766	957766	0	0.0
			(read/write)	1393810	1393810	0	0.0
			.dram0.bss	63576	63576	0	0.0
			.dram0.data	14220	14220	0	0.0
			.flash.rodata	197096	197096	0	0.0
			.flash.text	957766	957766	0	0.0
			.iram0.text	62016	62016	0	0.0
		m5stack	(read only)	1012875	1012875	0	0.0
			(read/write)	461052	461052	0	0.0
			.dram0.bss	69096	69096	0	0.0
			.dram0.data	34064	34064	0	0.0
			.flash.rodata	226056	226056	0	0.0
			.flash.text	1007491	1007491	0	0.0
			.iram0.text	123107	123107	0	0.0
k32w	light	k32w061+release	(read/write)	694464	694464	0	0.0
			.bss	77152	77152	0	0.0
			.data	1924	1924	0	0.0
			.text	609588	609588	0	0.0
	lock	k32w061+release	(read/write)	695324	695324	0	0.0
			.bss	77072	77072	0	0.0
			.data	1964	1964	0	0.0
			.text	610488	610488	0	0.0
linux	chip-tool-ipv6only	arm64	(read only)	9728988	9728988	0	0.0
			(read/write)	475953	475953	0	0.0
			.bss	43953	43953	0	0.0
			.data	1200	1200	0	0.0
			.data.rel.ro	371712	371712	0	0.0
			.dynamic	560	560	0	0.0
			.got	55296	55296	0	0.0
			.init	24	24	0	0.0
			.init_array	192	192	0	0.0
			.rodata	492084	492084	0	0.0
			.text	8185732	8185732	0	0.0
	thermostat-no-ble	arm64	(read only)	2178892	2178892	0	0.0
			(read/write)	148801	148801	0	0.0
			.bss	65393	65393	0	0.0
			.data	1048	1048	0	0.0
			.data.rel.ro	75160	75160	0	0.0
			.dynamic	560	560	0	0.0
			.got	4232	4232	0	0.0
			.init	24	24	0	0.0
			.init_array	352	352	0	0.0
			.rodata	133132	133132	0	0.0
			.text	1827184	1827184	0	0.0
mbed	lock-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2351484	2351484	0	0.0
			.bss	186212	186212	0	0.0
			.data	5792	5792	0	0.0
			.text	1314084	1314084	0	0.0
p6	all-clusters-app	default	(read/write)	2494296	2494296	0	0.0
			.bss	119640	119640	0	0.0
			.data	2680	2680	0	0.0
			.text	1452560	1452560	0	0.0
	light-app	default	(read/write)	2398312	2398312	0	0.0
			.bss	113104	113104	0	0.0
			.data	2536	2536	0	0.0
			.text	1356576	1356576	0	0.0
	lock-app	default	(read/write)	2361856	2361856	0	0.0
			.bss	112848	112848	0	0.0
			.data	2496	2496	0	0.0
			.text	1320120	1320120	0	0.0
telink	lighting-app	tlsr9518adk80d	(read/write)	888878	888878	0	0.0
			bss	86968	86968	0	0.0
			noinit	37160	37160	0	0.0
			text	628158	628158	0	0.0

[bzbarsky-apple]

Fast tracking platform change.