picoev: fix wrong return on failure

[felipensp]

Fix #22292

Just noticed running examples/veb/veb_assets/vweb_assets.v

_{Huly®: V_0.6-20922}

[spytheman]

Good find.
Would not just listening_socket_fd := listen(config)! work, or is the error hidden otherwise?

[esquerbatua]

Good find. Would not just listening_socket_fd := listen(config)! work, or is the error hidden otherwise?

The error should happens also, because it's from the picoev spawned thread, when makes the first event loop without the socket created