Fix T.Fatal inside a goroutine in tests

[janos]

This PR addresses test issues in #1055 for:

• swarm simulation
• stream
• netstore

swarm/network/simulation/events_test.go:84:2: the goroutine calls T.Fatal, which must be called in the same goroutine as the test (SA2002)
swarm/network/simulation/http_test.go:76:2: the goroutine calls T.Fatalf, which must be called in the same goroutine as the test (SA2002)
swarm/network/simulation/http_test.go:76:2: the goroutine calls T.Fatalf, which must be called in the same goroutine as the test (SA2002)
swarm/network/stream/delivery_test.go:556:3: the goroutine calls T.Fatalf, which must be called in the same goroutine as the test (SA2002)
swarm/network/stream/delivery_test.go:573:3: the goroutine calls T.Fatal, which must be called in the same goroutine as the test (SA2002)
swarm/network/stream/delivery_test.go:705:3: the goroutine calls T.Fatal, which must be called in the same goroutine as the test (SA2002)
swarm/network/stream/intervals_test.go:166:3: the goroutine calls T.Fatal, which must be called in the same goroutine as the test (SA2002)
swarm/network/stream/snapshot_sync_test.go:218:2: the goroutine calls T.Fatal, which must be called in the same goroutine as the test (SA2002)
swarm/network/stream/snapshot_sync_test.go:401:2: the goroutine calls T.Fatal, which must be called in the same goroutine as the test (SA2002)
swarm/network/stream/syncer_test.go:147:3: the goroutine calls T.Fatal, which must be called in the same goroutine as the test (SA2002)
swarm/storage/netstore_test.go:117:2: the goroutine calls T.Fatal, which must be called in the same goroutine as the test (SA2002)
swarm/storage/netstore_test.go:117:2: the goroutine calls T.Fatalf, which must be called in the same goroutine as the test (SA2002)
swarm/storage/netstore_test.go:203:2: the goroutine calls T.Fatal, which must be called in the same goroutine as the test (SA2002)
swarm/storage/netstore_test.go:246:2: the goroutine calls T.Fatal, which must be called in the same goroutine as the test (SA2002)
swarm/storage/netstore_test.go:289:2: the goroutine calls T.Fatal, which must be called in the same goroutine as the test (SA2002)
swarm/storage/netstore_test.go:289:2: the goroutine calls T.Fatalf, which must be called in the same goroutine as the test (SA2002)
swarm/storage/netstore_test.go:306:3: the goroutine calls T.Fatalf, which must be called in the same goroutine as the test (SA2002)
swarm/storage/netstore_test.go:306:3: the goroutine calls T.Fatalf, which must be called in the same goroutine as the test (SA2002)
swarm/storage/netstore_test.go:549:3: the goroutine calls T.Fatalf, which must be called in the same goroutine as the test (SA2002)
swarm/storage/netstore_test.go:613:3: the goroutine calls T.Fatalf, which must be called in the same goroutine as the test (SA2002)

[frncmx]

just minor things I commented on
LGTM

[frncmx]

Thank you, @janos! Ship it.

[janos]

Thank you all for review. It is submitted upstream ethereum/go-ethereum#18409.

[zelig]

merged as ethereum/go-ethereum#18409