libcontainer: logs: safely close channel and ensure error propagation in ForwardLogs in logs.go

[AntonMoryakov]

Static analyzer reported:
Use of value 'done' at logs.go:38 after release at logs.go:35 by calling function 'logs.ForwardLogs$1' at logs.go:25.

Corrections explained:

• Added defer close(done) to ensure the channel is closed after the goroutine finishes.
• Removed explicit close(done) after sending the error to avoid potential panics.
• Ensured that errors from s.Scan() are properly propagated to the done channel.

Triggers found by static analyzer Svace.

Signed-off-by: Anton Moryakov [email protected]

[cyphar]

The static analyser is wrong here, the code is being run in a goroutine so it's not "used after" and this pattern is an incredibly common Go pattern. Given that the analyser appears to not understand goroutines (or inline functions?), I wonder if the defer close(...) line is silencing it because the analyser thinks that go func() { ... }() is a regular scope (it isn't).

AFAICS there is no need to do a defer here (yes, defer is no longer a performance issue in Go but I don't think it makes the code easier to understand).