Meson

nixd/lib/Controller: use `CheckReturn` to simplify early-returns (NFC) #3258

Job	Run time
nix-build-develop-clang (none, release, true)	2m 59s
nix-build-develop-gcc (none, release, true)	3m 0s
nix-build-develop-clang (none, release, false)	2m 53s
nix-build-develop-gcc (none, release, false)	3m 0s
nix-build-develop-clang (none, debug, true)	2m 45s
nix-build-develop-gcc (none, debug, true)	2m 57s
nix-build-develop-clang (none, debug, false)	2m 41s
nix-build-develop-gcc (none, debug, false)	3m 1s
nix-build-develop-gcc (address, release, true)	4m 40s
nix-build-develop-gcc (address, release, false)	4m 46s
nix-build-develop-gcc (address, debug, true)	3m 57s
nix-build-develop-gcc (address, debug, false)	4m 1s
nix-build-develop-gcc (undefined, release, true)	4m 13s
nix-build-develop-gcc (undefined, release, false)	4m 10s
nix-build-develop-gcc (undefined, debug, true)	3m 12s
nix-build-develop-gcc (undefined, debug, false)	3m 21s
	55m 36s

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