fix(tty): handle SendSignal error to prevent infinite loop

[GHOryy5]

The Issue
In CheckChange, the code ignores the error from SendSignal and returns ERESTARTSYS.
In Linux, TIF_SIGPENDING is set unconditionally, ensuring the loop breaks.
In gVisor, if SendSignal fails, no signal is pending. Returning ERESTARTSYS causes the syscall to restart immediately, leading to an infinite loop (DoS).

The Fix
I added an error check. If SendSignal fails, we return EIO to abort the syscall safely.

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